Store idents for `DefPathData` into crate metadata

Previously, we threw away the `Span` associated with a definition's
identifier when we encoded crate metadata, causing us to lose location
and hygiene information.

We now store the identifier's `Span` in the crate metadata.
When we decode items from the metadata, we combine
the name and span back into an `Ident`.

This improves the output of several tests, which previously had messages
suppressed due to dummy spans.

This is a prerequisite for #68686, since throwing away a `Span` means
that we lose hygiene information.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs
index 77d6e4560ab..d29ec83bfa0 100644
--- a/src/librustc_resolve/build_reduced_graph.rs
+++ b/src/librustc_resolve/build_reduced_graph.rs
@@ -904,7 +904,10 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 self.insert_field_names(def_id, field_names);
             }
             Res::Def(DefKind::AssocFn, def_id) => {
-                if cstore.associated_item_cloned_untracked(def_id).method_has_self_argument {
+                if cstore
+                    .associated_item_cloned_untracked(def_id, self.r.session)
+                    .method_has_self_argument
+                {
                     self.r.has_self.insert(def_id);
                 }
             }