[clang] [Clang][Parser] Remove the concept from the DeclContext if the definition is invalid (PR #111179)

[Shafik Yaghmour via cfe-commits]

================
@@ -337,6 +343,8 @@ Parser::ParseConceptDefinition(const ParsedTemplateInfo &TemplateInfo,
   ExprResult ConstraintExprResult =
       Actions.CorrectDelayedTyposInExpr(ParseConstraintExpression());
   if (ConstraintExprResult.isInvalid()) {
+    if (AddedToScope)
----------------
shafik wrote:

I really don't like the `AddedToScope` pass by reference and I am wondering why we can't do this inside of `ActOnStartConceptDefinition`

https://github.com/llvm/llvm-project/pull/111179