[clang] [Clang] Fix assertion failure in getASTRecordLayout for invalid declarations (PR #208153)

[Aaron Ballman via cfe-commits]

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@@ -3384,9 +3384,30 @@ ASTContext::getASTRecordLayout(const RecordDecl *D) const {
   // not a complete definition (which is what isCompleteDefinition() tests)
   // until we *finish* parsing the definition.
   D = D->getDefinition();
-  assert(D && "Cannot get layout of forward declarations!");
-  assert(!D->isInvalidDecl() && "Cannot get layout of invalid decl!");
-  assert(D->isCompleteDefinition() && "Cannot layout type before complete!");
+
+  // Handle invalid declarations gracefully during error recovery
+  // This can happen when there are template specialization errors
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AaronBallman wrote:

Why is the correct fix not to stop asking for the record layout of an invalid object in that case?

(We might still want these changes anyway because now we have things like clang-repl, but it seems odd to me that template specialization errors would warrant a change.)

https://github.com/llvm/llvm-project/pull/208153