Add Rustc prefixes to derive(Decodable, Encodable).

As a bit of a hack, make `rustc_serialize` an alias of the private
`serialize` crate, just so the new derive continues working.

Fix #54287.

src/test/run-pass-fulldeps/deriving-encodable-decodable-box.rs

@@ -14,11 +14,12 @@
 #![feature(rustc_private)]
 
 extern crate serialize;
+use serialize as rustc_serialize;
 
 use serialize::{Encodable, Decodable};
 use serialize::json;
 
-#[derive(Encodable, Decodable)]
+#[derive(RustcEncodable, RustcDecodable)]
 struct A {
     foo: Box<[bool]>,
 }

src/test/run-pass-fulldeps/deriving-encodable-decodable-cell-refcell.rs

@@ -16,17 +16,18 @@
 #![feature(rustc_private)]
 
 extern crate serialize;
+use serialize as rustc_serialize;
 
 use std::cell::{Cell, RefCell};
 use serialize::{Encodable, Decodable};
 use serialize::json;
 
-#[derive(Encodable, Decodable)]
+#[derive(RustcEncodable, RustcDecodable)]
 struct A {
     baz: isize
 }
 
-#[derive(Encodable, Decodable)]
+#[derive(RustcEncodable, RustcDecodable)]
 struct B {
     foo: Cell<bool>,
     bar: RefCell<A>,

src/test/run-pass-fulldeps/deriving-global.rs

@@ -11,6 +11,7 @@
 #![feature(rustc_private)]
 
 extern crate serialize;
+use serialize as rustc_serialize;
 
 mod submod {
     // if any of these are implemented without global calls for any
@@ -20,21 +21,21 @@ mod submod {
                Hash,
                Clone,
                Debug,
-               Encodable, Decodable)]
+               RustcEncodable, RustcDecodable)]
     enum A { A1(usize), A2(isize) }
 
     #[derive(PartialEq, PartialOrd, Eq, Ord,
                Hash,
                Clone,
                Debug,
-               Encodable, Decodable)]
+               RustcEncodable, RustcDecodable)]
     struct B { x: usize, y: isize }
 
     #[derive(PartialEq, PartialOrd, Eq, Ord,
                Hash,
                Clone,
                Debug,
-               Encodable, Decodable)]
+               RustcEncodable, RustcDecodable)]
     struct C(usize, isize);
 
 }

src/test/run-pass-fulldeps/deriving-hygiene.rs

@@ -11,6 +11,7 @@
 #![allow(non_upper_case_globals)]
 #![feature(rustc_private)]
 extern crate serialize;
+use serialize as rustc_serialize;
 
 pub const other: u8 = 1;
 pub const f: u8 = 1;
@@ -19,7 +20,7 @@ pub const s: u8 = 1;
 pub const state: u8 = 1;
 pub const cmp: u8 = 1;
 
-#[derive(Ord,Eq,PartialOrd,PartialEq,Debug,Decodable,Encodable,Hash)]
+#[derive(Ord,Eq,PartialOrd,PartialEq,Debug,RustcDecodable,RustcEncodable,Hash)]
 struct Foo {}
 
 fn main() {

src/test/run-pass-fulldeps/issue-11881.rs

@@ -15,6 +15,7 @@
 #![feature(rustc_private)]
 
 extern crate serialize;
+use serialize as rustc_serialize;
 
 use std::io::Cursor;
 use std::io::prelude::*;
@@ -25,12 +26,12 @@ use serialize::{Encodable, Encoder};
 use serialize::json;
 use serialize::opaque;
 
-#[derive(Encodable)]
+#[derive(RustcEncodable)]
 struct Foo {
     baz: bool,
 }
 
-#[derive(Encodable)]
+#[derive(RustcEncodable)]
 struct Bar {
     froboz: usize,
 }

src/test/run-pass-fulldeps/issue-14021.rs

@@ -13,11 +13,12 @@
 #![feature(rustc_private)]
 
 extern crate serialize;
+extern crate serialize as rustc_serialize;
 
 use serialize::{Encodable, Decodable};
 use serialize::json;
 
-#[derive(Encodable, Decodable, PartialEq, Debug)]
+#[derive(RustcEncodable, RustcDecodable, PartialEq, Debug)]
 struct UnitLikeStruct;
 
 pub fn main() {