[clang] [BoundsSafety][Clang][Sema][AST] Introduce CThisExpr for C __counted_by attributes (PR #199241)

[Oliver Hunt via cfe-commits]

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@@ -4334,6 +4345,7 @@ bool Expr::isSameComparisonOperand(const Expr* E1, const Expr* E2) {
   switch (E1->getStmtClass()) {
     default:
       return false;
+    case CThisExprClass:
     case CXXThisExprClass:
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ojhunt wrote:

is this correct? can you give an example of where this occurs?

https://github.com/llvm/llvm-project/pull/199241