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, 2 insertions, 2 deletions

diff --git a/src/librustdoc/html/render/print_item.rs b/src/librustdoc/html/render/print_item.rs
index 9f2830ba542..c8ae5bf1f02 100644
--- a/src/librustdoc/html/render/print_item.rs
+++ b/src/librustdoc/html/render/print_item.rs
@@ -1776,8 +1776,8 @@ fn document_type_layout(w: &mut Buffer, cx: &Context<'_>, ty_def_id: DefId) {
                     };
 
                     for (index, layout) in variants.iter_enumerated() {
-                        let ident = adt.variants[index].ident;
-                        write!(w, "<li><code>{name}</code>: ", name = ident);
+                        let name = adt.variants[index].name;
+                        write!(w, "<li><code>{name}</code>: ", name = name);
                         write_size_of_layout(w, layout, tag_size);
                         writeln!(w, "</li>");
                     }