[clang] [Clang] Fix new initializer list mangling (PR #232629)

[Oliver Hunt via cfe-commits]

================
@@ -1531,7 +1531,8 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
   if (LangOpts.OpenMP)
     OpenMP().ActOnFinishedFunctionDefinitionInOpenMPAssumeScope(Method);
 
-  handleLambdaNumbering(Class, Method);
+  if (!Method->getType()->containsErrors())
----------------
ojhunt wrote:

This guard seems unrelated to initializer mangling - _if_ you have a test case that was able to break this independently of the initializer list mangling I think it would be worth splitting this change out

https://github.com/llvm/llvm-project/pull/232629