[clang] Fix crash on defaulted comparison recovery in Sema and AST (PR #210668)

[purnima shrivastava via cfe-commits]

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@@ -3138,6 +3138,11 @@ FunctionDecl::DefaultedOrDeletedFunctionInfo::Create(
 void FunctionDecl::setDefaultedOrDeletedInfo(
     DefaultedOrDeletedFunctionInfo *Info) {
   assert(!FunctionDeclBits.HasDefaultedOrDeletedInfo && "already have this");
+
+  // Guard against assertions tripping during error-recovery states
+  if (isInvalidDecl() || Body)
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purnima-nlp wrote:

I see , i just suppressed the assertion but I should have thought about the complete backward flow , the root cause of this bug.
Thanks for your feedback, I'm actively working on this. 

https://github.com/llvm/llvm-project/pull/210668