[clang] [clang] Fix C++20 list initialization of const references to arrays of unknown bound (PR #218225)

[Ahmed Zihan Hossain via cfe-commits]

================
@@ -48,3 +48,21 @@ void gh151716_f() {
 }
 
 } // namespace One
+
+namespace Two {
+
+void unknownBoundArrayRef(const int (&)[]);
----------------
zihan001 wrote:

rvalue ref cases are already covered. I added sema test for const and non-const lvalue refs.

https://github.com/llvm/llvm-project/pull/218225