[clang] [clang][Sema] Preserve the initializer of invalid VarDecls (PR #88645)

[Nathan Ridge via cfe-commits]

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@@ -13435,16 +13435,18 @@ void Sema::checkNonTrivialCUnion(QualType QT, SourceLocation Loc,
 void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
   // If there is no declaration, there was an error parsing it.  Just ignore
   // the initializer.
-  if (!RealDecl || RealDecl->isInvalidDecl()) {
+  if (!RealDecl) {
     CorrectDelayedTyposInExpr(Init, dyn_cast_or_null<VarDecl>(RealDecl));
     return;
   }
 
   if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) {
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HighCommander4 wrote:

Actually, that's not quite right, either. There is a `return;` that we want to take for any method, and a diagnostic for the `!Method->isInvalidDecl()` case. We therefore do need two nested `if`s.

https://github.com/llvm/llvm-project/pull/88645