Rollup merge of #146251 - hkBst:clippy-fix-8, r=cjgillot

rustc_middle: clippy fixes
Fixes for:
```text
warning: bound is defined in more than one place
warning: empty line after doc comment
```

Author: matthiaskrgr

compiler/rustc_middle/src/mir/consts.rs

@@ -579,7 +579,7 @@ impl<'tcx> Display for Const<'tcx> {
 }
 
 ///////////////////////////////////////////////////////////////////////////
-/// Const-related utilities
+// Const-related utilities
 
 impl<'tcx>TyCtxt<'tcx>{
 pubfnspan_as_caller_location(self,span:Span) -> ConstValue{

compiler/rustc_middle/src/mir/statement.rs

@@ -408,14 +408,14 @@ impl<'tcx> Place<'tcx> {
 self.as_ref().project_deeper(more_projections, tcx)
 }
 
-pubfnty_from<D: ?Sized>(
+pubfnty_from<D>(
 local:Local,
 projection:&[PlaceElem<'tcx>],
 local_decls:&D,
 tcx:TyCtxt<'tcx>,
 ) -> PlaceTy<'tcx>
 where
-D:HasLocalDecls<'tcx>,
+D:?Sized + HasLocalDecls<'tcx>,
 {
 PlaceTy::from_ty(local_decls.local_decls()[local].ty).multi_projection_ty(tcx, projection)
 }
@@ -529,9 +529,9 @@ impl<'tcx> PlaceRef<'tcx> {
 Place{local:self.local,projection: tcx.mk_place_elems(new_projections)}
 }
 
-pubfnty<D: ?Sized>(&self,local_decls:&D,tcx:TyCtxt<'tcx>) -> PlaceTy<'tcx>
+pubfnty<D>(&self,local_decls:&D,tcx:TyCtxt<'tcx>) -> PlaceTy<'tcx>
 where
-D:HasLocalDecls<'tcx>,
+D:?Sized + HasLocalDecls<'tcx>,
 {
 Place::ty_from(self.local,self.projection, local_decls, tcx)
 }
@@ -630,19 +630,19 @@ impl<'tcx> Operand<'tcx> {
 iflet ty::FnDef(def_id, args) = *const_ty.kind(){Some((def_id, args))}else{None}
 }
 
-pubfnty<D: ?Sized>(&self,local_decls:&D,tcx:TyCtxt<'tcx>) -> Ty<'tcx>
+pubfnty<D>(&self,local_decls:&D,tcx:TyCtxt<'tcx>) -> Ty<'tcx>
 where
-D:HasLocalDecls<'tcx>,
+D:?Sized + HasLocalDecls<'tcx>,
 {
 matchself{
 &Operand::Copy(ref l) | &Operand::Move(ref l) => l.ty(local_decls, tcx).ty,
 Operand::Constant(c) => c.const_.ty(),
 }
 }
 
-pubfnspan<D: ?Sized>(&self,local_decls:&D) -> Span
+pubfnspan<D>(&self,local_decls:&D) -> Span
 where
-D:HasLocalDecls<'tcx>,
+D:?Sized + HasLocalDecls<'tcx>,
 {
 matchself{
 &Operand::Copy(ref l) | &Operand::Move(ref l) => {
@@ -674,7 +674,7 @@ impl<'tcx> ConstOperand<'tcx> {
 }
 
 ///////////////////////////////////////////////////////////////////////////
-/// Rvalues
+// Rvalues
 
 pubenumRvalueInitializationState{
 Shallow,
@@ -721,9 +721,9 @@ impl<'tcx> Rvalue<'tcx> {
 }
 }
 
-pubfnty<D: ?Sized>(&self,local_decls:&D,tcx:TyCtxt<'tcx>) -> Ty<'tcx>
+pubfnty<D>(&self,local_decls:&D,tcx:TyCtxt<'tcx>) -> Ty<'tcx>
 where
-D:HasLocalDecls<'tcx>,
+D:?Sized + HasLocalDecls<'tcx>,
 {
 match*self{
 Rvalue::Use(ref operand) => operand.ty(local_decls, tcx),

compiler/rustc_middle/src/ty/codec.rs

@@ -216,10 +216,7 @@ impl<'tcx, E: TyEncoder<'tcx>> Encodable<E> for ty::ParamEnv<'tcx> {
 #[inline]
 fndecode_arena_allocable<'tcx,D:TyDecoder<'tcx>,T:ArenaAllocatable<'tcx> + Decodable<D>>(
 decoder:&mutD,
-) -> &'tcxT
-where
-D:TyDecoder<'tcx>,
-{
+) -> &'tcxT{
  decoder.interner().arena.alloc(Decodable::decode(decoder))
 }
 
@@ -230,10 +227,7 @@ fn decode_arena_allocable_slice<
 T:ArenaAllocatable<'tcx> + Decodable<D>,
 >(
 decoder:&mutD,
-) -> &'tcx[T]
-where
-D:TyDecoder<'tcx>,
-{
+) -> &'tcx[T]{
  decoder.interner().arena.alloc_from_iter(<Vec<T>asDecodable<D>>::decode(decoder))
 }