Suppress some fallout from gen in synstructure

compiler/rustc_macros/src/diagnostics/diagnostic.rs

@@ -71,6 +71,8 @@ impl<'a> DiagnosticDerive<'a> {
         });
 
         // A lifetime of `'a` causes conflicts, but `_sess` is fine.
+        // FIXME(edition_2024): Fix the `keyword_idents_2024` lint to not trigger here?
+        #[allow(keyword_idents_2024)]
         let mut imp = structure.gen_impl(quote! {
             gen impl<'_sess, G> rustc_errors::Diagnostic<'_sess, G> for @Self
                 where G: rustc_errors::EmissionGuarantee
@@ -148,6 +150,8 @@ impl<'a> LintDiagnosticDerive<'a> {
             }
         });
 
+        // FIXME(edition_2024): Fix the `keyword_idents_2024` lint to not trigger here?
+        #[allow(keyword_idents_2024)]
         let mut imp = structure.gen_impl(quote! {
             gen impl<'__a> rustc_errors::LintDiagnostic<'__a, ()> for @Self {
                 #[track_caller]

compiler/rustc_macros/src/diagnostics/subdiagnostic.rs

@@ -86,6 +86,9 @@ impl SubdiagnosticDerive {
 
         let diag = &self.diag;
         let f = &self.f;
+
+        // FIXME(edition_2024): Fix the `keyword_idents_2024` lint to not trigger here?
+        #[allow(keyword_idents_2024)]
         let ret = structure.gen_impl(quote! {
             gen impl rustc_errors::Subdiagnostic for @Self {
                 fn add_to_diag_with<__G, __F>(
@@ -100,6 +103,7 @@ impl SubdiagnosticDerive {
                 }
             }
         });
+
         ret
     }
 }