Simplify tls::enter_context.

compiler/rustc_interface/src/callbacks.rs

@@ -38,7 +38,7 @@ fn track_diagnostic(diagnostic: &mut Diagnostic, f: &mut dyn FnMut(&mut Diagnost
 
             // Diagnostics are tracked, we can ignore the dependency.
             let icx = tls::ImplicitCtxt { task_deps: TaskDepsRef::Ignore, ..icx.clone() };
-            return tls::enter_context(&icx, move |_| (*f)(diagnostic));
+            return tls::enter_context(&icx, move || (*f)(diagnostic));
         }
 
         // In any other case, invoke diagnostics anyway.

compiler/rustc_interface/src/passes.rs

@@ -748,7 +748,7 @@ impl<'tcx> QueryContext<'tcx> {
         F: FnOnce(TyCtxt<'tcx>) -> R,
     {
         let icx = ty::tls::ImplicitCtxt::new(self.gcx);
-        ty::tls::enter_context(&icx, |_| f(icx.tcx))
+        ty::tls::enter_context(&icx, || f(icx.tcx))
     }
 }
 

compiler/rustc_middle/src/dep_graph/mod.rs

@@ -55,7 +55,7 @@ impl rustc_query_system::dep_graph::DepKind for DepKind {
         ty::tls::with_context(|icx| {
             let icx = ty::tls::ImplicitCtxt { task_deps, ..icx.clone() };
 
-            ty::tls::enter_context(&icx, |_| op())
+            ty::tls::enter_context(&icx, op)
         })
     }
 

compiler/rustc_middle/src/ty/context/tls.rs

@@ -110,9 +110,9 @@ unsafe fn downcast<'a, 'tcx>(context: *const ()) -> &'a ImplicitCtxt<'a, 'tcx> {
 #[inline]
 pub fn enter_context<'a, 'tcx, F, R>(context: &ImplicitCtxt<'a, 'tcx>, f: F) -> R
 where
-    F: FnOnce(&ImplicitCtxt<'a, 'tcx>) -> R,
+    F: FnOnce() -> R,
 {
-    tlv::with_tlv(erase(context), || f(&context))
+    tlv::with_tlv(erase(context), f)
 }
 
 /// Allows access to the current `ImplicitCtxt` in a closure if one is available.

compiler/rustc_query_impl/src/plumbing.rs

@@ -124,7 +124,7 @@ impl QueryContext for QueryCtxt<'_> {
             };
 
             // Use the `ImplicitCtxt` while we execute the query.
-            tls::enter_context(&new_icx, |_| {
+            tls::enter_context(&new_icx, || {
                 rustc_data_structures::stack::ensure_sufficient_stack(compute)
             })
         })