Store a `Symbol` instead of an `Ident` in `VariantDef`/`FieldDef`

The field is also renamed from `ident` to `name. In most cases,
we don't actually need the `Span`. A new `ident` method is added
to `VariantDef` and `FieldDef`, which constructs the full `Ident`
using `tcx.def_ident_span()`. This method is used in the cases
where we actually need an `Ident`.

This makes incremental compilation properly track changes
to the `Span`, without all of the invalidations caused by storing
a `Span` directly via an `Ident`.

1 files changed, 3 insertions, 3 deletions

diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs
index 5a398c2f45a..9dc7930fc51 100644
--- a/compiler/rustc_const_eval/src/interpret/validity.rs
+++ b/compiler/rustc_const_eval/src/interpret/validity.rs
@@ -267,14 +267,14 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
                 match layout.variants {
                     Variants::Single { index } => {
                         // Inside a variant
-                        PathElem::Field(def.variants[index].fields[field].ident.name)
+                        PathElem::Field(def.variants[index].fields[field].name)
                     }
                     Variants::Multiple { .. } => bug!("we handled variants above"),
                 }
             }
 
             // other ADTs
-            ty::Adt(def, _) => PathElem::Field(def.non_enum_variant().fields[field].ident.name),
+            ty::Adt(def, _) => PathElem::Field(def.non_enum_variant().fields[field].name),
 
             // arrays/slices
             ty::Array(..) | ty::Slice(..) => PathElem::ArrayElem(field),
@@ -726,7 +726,7 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValueVisitor<'mir, 'tcx, M>
         new_op: &OpTy<'tcx, M::PointerTag>,
     ) -> InterpResult<'tcx> {
         let name = match old_op.layout.ty.kind() {
-            ty::Adt(adt, _) => PathElem::Variant(adt.variants[variant_id].ident.name),
+            ty::Adt(adt, _) => PathElem::Variant(adt.variants[variant_id].name),
             // Generators also have variants
             ty::Generator(..) => PathElem::GeneratorState(variant_id),
             _ => bug!("Unexpected type with variant: {:?}", old_op.layout.ty),