[clang] [Clang] prevent assertion failure by avoiding required literal type checking in C context (PR #101426)

[Mariya Podchishchaeva via cfe-commits]

================
@@ -9267,14 +9267,14 @@ bool Sema::RequireLiteralType(SourceLocation Loc, QualType T,
   if (!RT)
     return true;
 
-  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
-
   // A partially-defined class type can't be a literal type, because a literal
   // class type must have a trivial destructor (which can't be checked until
   // the class definition is complete).
   if (RequireCompleteType(Loc, ElemType, diag::note_non_literal_incomplete, T))
     return true;
 
+  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
----------------
Fznamznon wrote:

> should I move const CXXRecordDecl *RD back to its original position after RequireCompleteType?

I think yes. It also makes sense to add `assert(LangOpts.CPlusPlus)` in the beginning of `RequireLiteralType` as @MitalAshok already mentioned.

https://github.com/llvm/llvm-project/pull/101426