Remove the let_else feature gate from the testsuite

Result of running:

rg -l "feature.let_else" src/test/  | xargs sed -s -i "s#^...feature.let_else..\$##"

Plus manual tidy fixes.

src/test/ui/async-await/async-await-let-else.rs

@@ -2,7 +2,7 @@
 // revisions: drop-tracking no-drop-tracking
 // [drop-tracking] compile-flags: -Zdrop-tracking=yes
 // [no-drop-tracking] compile-flags: -Zdrop-tracking=no
-#![feature(let_else)]
+
 use std::rc::Rc;
 
 async fn foo(x: Option<bool>) {

src/test/ui/let-else/issue-100103.rs

@@ -2,7 +2,7 @@
 // check-pass
 
 #![feature(try_blocks)]
-#![feature(let_else)]
+
 
 fn main() {
     let _: Result<i32, i32> = try {

src/test/ui/let-else/issue-94176.rs

@@ -1,6 +1,6 @@
 // Issue #94176: wrong span for the error message of a mismatched type error,
 // if the function uses a `let else` construct.
-#![feature(let_else)]
+
 
 pub fn test(a: Option<u32>) -> Option<u32> { //~ ERROR mismatched types
     let Some(_) = a else { return None; };

src/test/ui/let-else/issue-99975.rs

@@ -1,7 +1,7 @@
 // run-pass
 // compile-flags: -C opt-level=3 -Zvalidate-mir
 
-#![feature(let_else)]
+
 
 fn return_result() -> Option<String> {
     Some("ok".to_string())

src/test/ui/let-else/let-else-allow-in-expr.rs

@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 #![deny(unused_variables)]
 
 fn main() {

src/test/ui/let-else/let-else-allow-in-expr.stderr

@@ -1,17 +1,17 @@
 error: unused variable: `x`
-  --> $DIR/let-else-allow-in-expr.rs:7:13
+  --> $DIR/let-else-allow-in-expr.rs:5:13
    |
 LL |         let x = 1;
    |             ^ help: if this is intentional, prefix it with an underscore: `_x`
    |
 note: the lint level is defined here
-  --> $DIR/let-else-allow-in-expr.rs:3:9
+  --> $DIR/let-else-allow-in-expr.rs:1:9
    |
 LL | #![deny(unused_variables)]
    |         ^^^^^^^^^^^^^^^^
 
 error: unused variable: `x`
-  --> $DIR/let-else-allow-in-expr.rs:29:9
+  --> $DIR/let-else-allow-in-expr.rs:27:9
    |
 LL |     let x = 1;
    |         ^ help: if this is intentional, prefix it with an underscore: `_x`

src/test/ui/let-else/let-else-allow-unused.rs

@@ -1,6 +1,6 @@
 // issue #89807
 
-#![feature(let_else)]
+
 
 #[deny(unused_variables)]
 

src/test/ui/let-else/let-else-binding-explicit-mut-annotated.rs

@@ -1,6 +1,6 @@
 // from rfc2005 test suite
 
-#![feature(let_else)]
+
 
 // Verify the binding mode shifts - only when no `&` are auto-dereferenced is the
 // final default binding mode mutable.

src/test/ui/let-else/let-else-binding-explicit-mut-borrow.rs

@@ -1,8 +1,8 @@
-#![feature(let_else)]
-
 // Slightly different from explicit-mut-annotated -- this won't show an error until borrowck.
 // Should it show a type error instead?
 
+
+
 fn main() {
     let Some(n): &mut Option<i32> = &mut &Some(5i32) else {
         //~^ ERROR cannot borrow data in a `&` reference as mutable

src/test/ui/let-else/let-else-binding-explicit-mut-pass.rs

@@ -1,6 +1,6 @@
 // check-pass
 
-#![feature(let_else)]
+
 
 fn main() {
     let Some(n) = &mut &mut Some(5i32) else { return; };

src/test/ui/let-else/let-else-binding-explicit-mut.rs

@@ -1,6 +1,6 @@
 // from rfc2005 test suite
 
-#![feature(let_else)]
+
 
 // Verify the binding mode shifts - only when no `&` are auto-dereferenced is the
 // final default binding mode mutable.

src/test/ui/let-else/let-else-binding-immutable.rs

@@ -1,6 +1,6 @@
 // from rfc2005 test suite
 
-#![feature(let_else)]
+
 
 pub fn main() {
     let Some(x) = &Some(3) else {

src/test/ui/let-else/let-else-bindings.rs

@@ -1,6 +1,6 @@
 // run-pass
 // adapted from src/test/ui/binding/if-let.rs
-#![feature(let_else)]
+
 #![allow(dead_code)]
 
 fn none() -> bool {

src/test/ui/let-else/let-else-bool-binop-init.fixed

@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![feature(let_else)]
+
 
 fn main() {
     let true = (true && false) else { return }; //~ ERROR a `&&` expression cannot be directly assigned in `let...else`

src/test/ui/let-else/let-else-bool-binop-init.rs

@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![feature(let_else)]
+
 
 fn main() {
     let true = true && false else { return }; //~ ERROR a `&&` expression cannot be directly assigned in `let...else`

src/test/ui/let-else/let-else-brace-before-else.fixed

@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![feature(let_else)]
+
 
 fn main() {
     let Some(1) = ({ Some(1) }) else {

src/test/ui/let-else/let-else-brace-before-else.rs

@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![feature(let_else)]
+
 
 fn main() {
     let Some(1) = { Some(1) } else {

src/test/ui/let-else/let-else-check.rs

@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 #![deny(unused_variables)]
 
 fn main() {

src/test/ui/let-else/let-else-check.stderr

@@ -1,17 +1,17 @@
 error: unused variable: `x`
-  --> $DIR/let-else-check.rs:14:13
+  --> $DIR/let-else-check.rs:12:13
    |
 LL |         let x = 1;
    |             ^ help: if this is intentional, prefix it with an underscore: `_x`
    |
 note: the lint level is defined here
-  --> $DIR/let-else-check.rs:3:9
+  --> $DIR/let-else-check.rs:1:9
    |
 LL | #![deny(unused_variables)]
    |         ^^^^^^^^^^^^^^^^
 
 error: unused variable: `x`
-  --> $DIR/let-else-check.rs:18:9
+  --> $DIR/let-else-check.rs:16:9
    |
 LL |     let x = 1;
    |         ^ help: if this is intentional, prefix it with an underscore: `_x`

src/test/ui/let-else/let-else-deref-coercion-annotated.rs

@@ -6,7 +6,7 @@
 // Deref/DerefMut to Bar. You can do this with an irrefutable binding, so it should work with
 // let-else too.
 
-#![feature(let_else)]
+
 use std::ops::{Deref, DerefMut};
 
 struct Foo(Bar);

src/test/ui/let-else/let-else-deref-coercion.rs

@@ -3,7 +3,7 @@
 // We attempt to `let Bar::Present(_) = foo else { ... }` where foo is meant to Deref/DerefMut to
 // Bar. This fails, you must add a type annotation like `let _: &mut Bar = _ else { ... }`
 
-#![feature(let_else)]
+
 use std::ops::{Deref, DerefMut};
 
 struct Foo(Bar);

src/test/ui/let-else/let-else-destructuring.rs

@@ -1,4 +1,3 @@
-#![feature(let_else)]
 #[derive(Debug)]
 enum Foo {
     Done,

src/test/ui/let-else/let-else-destructuring.stderr

@@ -1,11 +1,11 @@
 error: <assignment> ... else { ... } is not allowed
-  --> $DIR/let-else-destructuring.rs:11:9
+  --> $DIR/let-else-destructuring.rs:10:9
    |
 LL |         &Foo::Nested(Some(value)) = value else { break };
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0070]: invalid left-hand side of assignment
-  --> $DIR/let-else-destructuring.rs:11:35
+  --> $DIR/let-else-destructuring.rs:10:35
    |
 LL |         &Foo::Nested(Some(value)) = value else { break };
    |         ------------------------- ^

src/test/ui/let-else/let-else-drop-order.rs

@@ -16,7 +16,7 @@
 // This is important as it's easy to update the stdout file
 // with a --bless and miss the impact of that change.
 
-#![feature(let_else)]
+
 #![allow(irrefutable_let_patterns)]
 
 use std::cell::RefCell;

src/test/ui/let-else/let-else-if.rs

@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 fn main() {
     let Some(_) = Some(()) else if true {
         //~^ ERROR conditional `else if` is not supported for `let...else`

src/test/ui/let-else/let-else-if.stderr

@@ -1,5 +1,5 @@
 error: conditional `else if` is not supported for `let...else`
-  --> $DIR/let-else-if.rs:4:33
+  --> $DIR/let-else-if.rs:2:33
    |
 LL |     let Some(_) = Some(()) else if true {
    |                                 ^^ expected `{`

src/test/ui/let-else/let-else-irrefutable.rs

@@ -1,6 +1,6 @@
 // check-pass
 
-#![feature(let_else)]
+
 
 fn main() {
     let x = 1 else { return }; //~ WARN irrefutable `let...else` pattern

src/test/ui/let-else/let-else-missing-semicolon.rs

@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 fn main() {
     let Some(x) = Some(1) else {
         return;

src/test/ui/let-else/let-else-missing-semicolon.stderr

@@ -1,5 +1,5 @@
 error: expected `;`, found keyword `let`
-  --> $DIR/let-else-missing-semicolon.rs:6:6
+  --> $DIR/let-else-missing-semicolon.rs:4:6
    |
 LL |     }
    |      ^ help: add `;` here
@@ -7,7 +7,7 @@ LL |     let _ = "";
    |     --- unexpected token
 
 error: expected `;`, found `}`
-  --> $DIR/let-else-missing-semicolon.rs:10:6
+  --> $DIR/let-else-missing-semicolon.rs:8:6
    |
 LL |     }
    |      ^ help: add `;` here

src/test/ui/let-else/let-else-no-double-error.rs

@@ -1,6 +1,6 @@
 // from rfc2005 test suite
 
-#![feature(let_else)]
+
 
 // Without caching type lookups in FnCtxt.resolve_ty_and_def_ufcs
 // the error below would be reported twice (once when checking

src/test/ui/let-else/let-else-non-copy.rs

@@ -10,7 +10,7 @@
 //
 // The move was due to mir::Place being Copy, but mir::VarDebugInfoContents not being Copy.
 
-#![feature(let_else)]
+
 
 #[derive(Copy, Clone)]
 struct Copyable;

src/test/ui/let-else/let-else-non-diverging.rs

@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 fn main() {
     let Some(x) = Some(1) else { //~ ERROR does not diverge
         Some(2)

src/test/ui/let-else/let-else-non-diverging.stderr

@@ -1,5 +1,5 @@
 error[E0308]: `else` clause of `let...else` does not diverge
-  --> $DIR/let-else-non-diverging.rs:4:32
+  --> $DIR/let-else-non-diverging.rs:2:32
    |
 LL |       let Some(x) = Some(1) else {
    |  ________________________________^
@@ -13,7 +13,7 @@ LL | |     };
    = help: ...or use `match` instead of `let...else`
 
 error[E0308]: `else` clause of `let...else` does not diverge
-  --> $DIR/let-else-non-diverging.rs:7:32
+  --> $DIR/let-else-non-diverging.rs:5:32
    |
 LL |       let Some(x) = Some(1) else {
    |  ________________________________^
@@ -29,7 +29,7 @@ LL | |     };
    = help: ...or use `match` instead of `let...else`
 
 error[E0308]: `else` clause of `let...else` does not diverge
-  --> $DIR/let-else-non-diverging.rs:12:32
+  --> $DIR/let-else-non-diverging.rs:10:32
    |
 LL |     let Some(x) = Some(1) else { Some(2) };
    |                                ^^^^^^^^^^^ expected `!`, found enum `Option`

src/test/ui/let-else/let-else-ref-bindings-pass.rs

@@ -1,6 +1,6 @@
 // check-pass
 
-#![feature(let_else)]
+
 #![allow(unused_variables)]
 
 fn ref_() {

src/test/ui/let-else/let-else-ref-bindings.rs

@@ -1,6 +1,6 @@
-#![feature(let_else)]
 #![allow(unused_variables)]
 
+
 fn ref_() {
     let bytes: Vec<u8> = b"Hello"[..].to_vec();
     let some = Some(bytes);

src/test/ui/let-else/let-else-run-pass.rs

@@ -1,6 +1,6 @@
 // run-pass
 
-#![feature(let_else)]
+
 
 fn main() {
     #[allow(dead_code)]

src/test/ui/let-else/let-else-scope.rs

@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 fn main() {
     let Some(x) = Some(2) else {
         panic!("{}", x); //~ ERROR cannot find value `x` in this scope

src/test/ui/let-else/let-else-scope.stderr

@@ -1,5 +1,5 @@
 error[E0425]: cannot find value `x` in this scope
-  --> $DIR/let-else-scope.rs:5:22
+  --> $DIR/let-else-scope.rs:3:22
    |
 LL |         panic!("{}", x);
    |                      ^ not found in this scope

src/test/ui/let-else/let-else-slicing-error.rs

@@ -1,5 +1,5 @@
 // issue #92069
-#![feature(let_else)]
+
 
 fn main() {
     let nums = vec![5, 4, 3, 2, 1];

src/test/ui/let-else/let-else-source-expr-nomove-pass.rs

@@ -1,7 +1,7 @@
 // run-pass
 // issue #89688
 
-#![feature(let_else)]
+
 
 fn example_let_else(value: Option<String>) {
     let Some(inner) = value else {

src/test/ui/let-else/let-else-temp-borrowck.rs

@@ -3,7 +3,7 @@
 // from issue #93951, where borrowck complained the temporary that `foo(&x)` was stored in was to
 // be dropped sometime after `x` was. It then suggested adding a semicolon that was already there.
 
-#![feature(let_else)]
+
 use std::fmt::Debug;
 
 fn foo<'a>(x: &'a str) -> Result<impl Debug + 'a, ()> {

src/test/ui/let-else/let-else-temporary-lifetime.rs

@@ -1,6 +1,5 @@
 // run-pass
 // compile-flags: -Zvalidate-mir
-#![feature(let_else)]
 
 use std::fmt::Display;
 use std::rc::Rc;

src/test/ui/let-else/let-else-then-diverge.rs

@@ -2,7 +2,7 @@
 // popped up in in #94012, where an alternative desugaring was
 // causing unreachable code errors
 
-#![feature(let_else)]
+
 #![deny(unused_variables)]
 #![deny(unreachable_code)]
 

src/test/ui/pattern/usefulness/top-level-alternation.rs

@@ -1,5 +1,3 @@
-#![feature(let_else)]
-
 #![deny(unreachable_patterns)]
 
 fn main() {

src/test/ui/pattern/usefulness/top-level-alternation.stderr

@@ -1,71 +1,71 @@
 error: unreachable pattern
-  --> $DIR/top-level-alternation.rs:6:23
+  --> $DIR/top-level-alternation.rs:4:23
    |
 LL |     while let 0..=2 | 1 = 0 {}
    |                       ^
    |
 note: the lint level is defined here
-  --> $DIR/top-level-alternation.rs:3:9
+  --> $DIR/top-level-alternation.rs:1:9
    |
 LL | #![deny(unreachable_patterns)]
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/top-level-alternation.rs:7:20
+  --> $DIR/top-level-alternation.rs:5:20
    |
 LL |     if let 0..=2 | 1 = 0 {}
    |                    ^
 
 error: unreachable pattern
-  --> $DIR/top-level-alternation.rs:11:15
+  --> $DIR/top-level-alternation.rs:9:15
    |
 LL |             | 0 => {}
    |               ^
 
 error: unreachable pattern
-  --> $DIR/top-level-alternation.rs:16:15
+  --> $DIR/top-level-alternation.rs:14:15
    |
 LL |             | Some(0) => {}
    |               ^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/top-level-alternation.rs:21:9
+  --> $DIR/top-level-alternation.rs:19:9
    |
 LL |         (0, 0) => {}
    |         ^^^^^^
 
 error: unreachable pattern
-  --> $DIR/top-level-alternation.rs:41:9
+  --> $DIR/top-level-alternation.rs:39:9
    |
 LL |         _ => {}
    |         ^
 
 error: unreachable pattern
-  --> $DIR/top-level-alternation.rs:45:9
+  --> $DIR/top-level-alternation.rs:43:9
    |
 LL |         Some(_) => {}
    |         ^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/top-level-alternation.rs:46:9
+  --> $DIR/top-level-alternation.rs:44:9
    |
 LL |         None => {}
    |         ^^^^
 
 error: unreachable pattern
-  --> $DIR/top-level-alternation.rs:51:9
+  --> $DIR/top-level-alternation.rs:49:9
    |
 LL |         None | Some(_) => {}
    |         ^^^^^^^^^^^^^^
 
 error: unreachable pattern
-  --> $DIR/top-level-alternation.rs:55:9
+  --> $DIR/top-level-alternation.rs:53:9
    |
 LL |         1..=2 => {},
    |         ^^^^^
 
 error: unreachable pattern
-  --> $DIR/top-level-alternation.rs:58:14
+  --> $DIR/top-level-alternation.rs:56:14
    |
 LL |     let (0 | 0) = 0 else { return };
    |              ^

src/test/ui/rfc-2497-if-let-chains/ensure-that-let-else-does-not-interact-with-let-chains.rs

@@ -1,4 +1,4 @@
-#![feature(let_chains, let_else)]
+#![feature(let_chains)]
 
 fn main() {
     let opt = Some(1i32);

src/test/ui/unpretty/pretty-let-else.rs

@@ -1,7 +1,7 @@
 // compile-flags: -Zunpretty=hir
 // check-pass
 
-#![feature(let_else)]
+
 
 fn foo(x: Option<u32>) {
     let Some(_) = x else { panic!() };

src/test/ui/unpretty/pretty-let-else.stdout

@@ -1,11 +1,11 @@
-// compile-flags: -Zunpretty=hir
-// check-pass
-
-#![feature(let_else)]
 #[prelude_import]
 use ::std::prelude::rust_2015::*;
 #[macro_use]
 extern crate std;
+// compile-flags: -Zunpretty=hir
+// check-pass
+
+
 
 fn foo(x:
         Option<u32>) {