[clang] [clang] implement current direction of CWG2765 for string literal comparisons in constant evaluation (PR #109208)

[Aaron Ballman via cfe-commits]

================
@@ -96,6 +96,8 @@ def note_constexpr_pointer_constant_comparison : Note<
   "at runtime">;
 def note_constexpr_literal_comparison : Note<
   "comparison of addresses of literals has unspecified value">;
+def note_constexpr_opaque_call_comparison : Note<
+  "comparison against opaque constant has unspecified value">;
----------------
AaronBallman wrote:

Yeah, opaque constant is pretty opaque, but I'm struggling to think of a better way to phrase this. It only triggers when calling a builtin which forms an address constant.

Mayyyybbbe: comparison against an anonymous object with a constant address has unspecified value

? (or maybe 'unnamed' instead of 'anonymous')

https://github.com/llvm/llvm-project/pull/109208