address review comment

See rust-lang#121067 (comment)

Author: tshepang

compiler/rustc_expand/messages.ftl

@@ -63,7 +63,7 @@ expand_invalid_cfg_no_predicate = `cfg` predicate is not specified
 expand_invalid_cfg_predicate_literal = `cfg` predicate key cannot be a literal
 
 expand_invalid_fragment_specifier =
-    invalid fragment specifier `{$name}`
+    invalid fragment specifier `{$fragment}`
     .help = {$help}
 
 expand_macro_body_stability =

compiler/rustc_expand/src/errors.rs

@@ -415,6 +415,6 @@ pub struct DuplicateMatcherBinding {
 pub struct InvalidFragmentSpecifier {
     #[primary_span]
     pub span: Span,
-    pub name: String,
+    pub fragment: Ident,
     pub help: String,
 }

compiler/rustc_expand/src/mbe/quoted.rs

@@ -61,11 +61,11 @@ pub(super) fn parse(
                     Some(&tokenstream::TokenTree::Token(Token { kind: token::Colon, span }, _)) => {
                         match trees.next() {
                             Some(tokenstream::TokenTree::Token(token, _)) => match token.ident() {
-                                Some((frag, _)) => {
+                                Some((fragment, _)) => {
                                     let span = token.span.with_lo(start_sp.lo());
 
                                     let kind =
-                                        token::NonterminalKind::from_symbol(frag.name, || {
+                                        token::NonterminalKind::from_symbol(fragment.name, || {
                                             // FIXME(#85708) - once we properly decode a foreign
                                             // crate's `SyntaxContext::root`, then we can replace
                                             // this with just `span.edition()`. A
@@ -85,7 +85,7 @@ pub(super) fn parse(
                                                 sess.dcx().emit_err(
                                                     errors::InvalidFragmentSpecifier {
                                                         span,
-                                                        name: frag.name.to_string(),
+                                                        fragment,
                                                         help: VALID_FRAGMENT_NAMES_MSG.into(),
                                                     },
                                                 );