[clang] [clang] fix error recovery for invalid member specializations (PR #207068)

[Erich Keane via cfe-commits]

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@@ -2209,7 +2201,7 @@ DeclResult Sema::CheckClassTemplate(
                         ? diag::err_friend_decl_does_not_match
                         : diag::err_member_decl_does_not_match)
           << Name << SemanticContext << /*IsDefinition*/ true << SS.getRange();
-      Invalid = true;
+      return true;
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erichkeane wrote:

just do `return Diag(...`? 

https://github.com/llvm/llvm-project/pull/207068