Rename and reorder lots of lifetimes.

- Replace non-standard names like 's, 'p, 'rg, 'ck, 'parent, 'this, and
  'me with vanilla 'a. These are cases where the original name isn't
  really any more informative than 'a.
- Replace names like 'cx, 'mir, and 'body with vanilla 'a when the lifetime
  applies to multiple fields and so the original lifetime name isn't
  really accurate.
- Put 'tcx last in lifetime lists, and 'a before 'b.

compiler/rustc_const_eval/src/check_consts/check.rs

@@ -166,12 +166,12 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
     }
 }
 
-struct LocalReturnTyVisitor<'ck, 'mir, 'tcx> {
+struct LocalReturnTyVisitor<'a, 'mir, 'tcx> {
     kind: LocalKind,
-    checker: &'ck mut Checker<'mir, 'tcx>,
+    checker: &'a mut Checker<'mir, 'tcx>,
 }
 
-impl<'ck, 'mir, 'tcx> TypeVisitor<TyCtxt<'tcx>> for LocalReturnTyVisitor<'ck, 'mir, 'tcx> {
+impl<'a, 'mir, 'tcx> TypeVisitor<TyCtxt<'tcx>> for LocalReturnTyVisitor<'a, 'mir, 'tcx> {
     fn visit_ty(&mut self, t: Ty<'tcx>) {
         match t.kind() {
             ty::FnPtr(..) => {}

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -1114,7 +1114,7 @@ impl<'a, 'tcx, M: Machine<'tcx>> std::fmt::Debug for DumpAllocs<'a, 'tcx, M> {
 }
 
 /// Reading and writing.
-impl<'tcx, 'a, Prov: Provenance, Extra, Bytes: AllocBytes>
+impl<'a, 'tcx, Prov: Provenance, Extra, Bytes: AllocBytes>
     AllocRefMut<'a, 'tcx, Prov, Extra, Bytes>
 {
     pub fn as_ref<'b>(&'b self) -> AllocRef<'b, 'tcx, Prov, Extra, Bytes> {
@@ -1162,7 +1162,7 @@ impl<'tcx, 'a, Prov: Provenance, Extra, Bytes: AllocBytes>
     }
 }
 
-impl<'tcx, 'a, Prov: Provenance, Extra, Bytes: AllocBytes> AllocRef<'a, 'tcx, Prov, Extra, Bytes> {
+impl<'a, 'tcx, Prov: Provenance, Extra, Bytes: AllocBytes> AllocRef<'a, 'tcx, Prov, Extra, Bytes> {
     /// `range` is relative to this allocation reference, not the base of the allocation.
     pub fn read_scalar(
         &self,

compiler/rustc_const_eval/src/interpret/projection.rs

@@ -101,7 +101,7 @@ pub trait Projectable<'tcx, Prov: Provenance>: Sized + std::fmt::Debug {
 }
 
 /// A type representing iteration over the elements of an array.
-pub struct ArrayIterator<'tcx, 'a, Prov: Provenance, P: Projectable<'tcx, Prov>> {
+pub struct ArrayIterator<'a, 'tcx, Prov: Provenance, P: Projectable<'tcx, Prov>> {
     base: &'a P,
     range: Range<u64>,
     stride: Size,
@@ -109,7 +109,7 @@ pub struct ArrayIterator<'tcx, 'a, Prov: Provenance, P: Projectable<'tcx, Prov>>
     _phantom: PhantomData<Prov>, // otherwise it says `Prov` is never used...
 }
 
-impl<'tcx, 'a, Prov: Provenance, P: Projectable<'tcx, Prov>> ArrayIterator<'tcx, 'a, Prov, P> {
+impl<'a, 'tcx, Prov: Provenance, P: Projectable<'tcx, Prov>> ArrayIterator<'a, 'tcx, Prov, P> {
     /// Should be the same `ecx` on each call, and match the one used to create the iterator.
     pub fn next<M: Machine<'tcx, Provenance = Prov>>(
         &mut self,
@@ -273,7 +273,7 @@ where
     pub fn project_array_fields<'a, P: Projectable<'tcx, M::Provenance>>(
         &self,
         base: &'a P,
-    ) -> InterpResult<'tcx, ArrayIterator<'tcx, 'a, M::Provenance, P>> {
+    ) -> InterpResult<'tcx, ArrayIterator<'a, 'tcx, M::Provenance, P>> {
         let abi::FieldsShape::Array { stride, .. } = base.layout().fields else {
             span_bug!(self.cur_span(), "project_array_fields: expected an array layout");
         };