Rename some name variables as ident.

It bugs me when variables of type `Ident` are called `name`. It leads to
silly things like `name.name`. `Ident` variables should be called
`ident`, and `name` should be used for variables of type `Symbol`.

This commit improves things by by doing `s/name/ident/` on a bunch of
`Ident` variables. Not all of them, but a decent chunk.

compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs

@@ -1988,7 +1988,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         {
             let closure: Vec<_> = self
                 .tcx
-                .fn_arg_names(fn_def_id)
+                .fn_arg_idents(fn_def_id)
                 .iter()
                 .enumerate()
                 .map(|(i, ident)| {
@@ -5397,7 +5397,7 @@ fn point_at_assoc_type_restriction<G: EmissionGuarantee>(
                 );
             }
             if let Some(new) =
-                tcx.associated_items(data.impl_or_alias_def_id).find_by_name_and_kind(
+                tcx.associated_items(data.impl_or_alias_def_id).find_by_ident_and_kind(
                     tcx,
                     Ident::with_dummy_span(name),
                     ty::AssocKind::Type,