[clang] [Clang] Preserve coroutine parameter referenced state (PR #70973)

[Chuanqi Xu via cfe-commits]

================
@@ -1965,9 +1965,15 @@ bool Sema::buildCoroutineParameterMoves(SourceLocation Loc) {
     if (PD->getType()->isDependentType())
       continue;
 
+    // Preserve the referenced state for unused parameter diagnostics.
+    bool DeclReferenced = PD->isReferenced();
----------------
ChuanqiXu9 wrote:

Cool.

https://github.com/llvm/llvm-project/pull/70973