[clang] [clang][Tests][NFC] Add CWG713 test; add example from CWG1584 test (PR #100747)

[Mital Ashok via cfe-commits]

MitalAshok wrote:

@Endilll The problem with the CWG713 test in Clang 18 was with parsing the type trait (#81298), they weren't actually considered `const`: https://godbolt.org/z/snde76brE

Also, I would think since the resolution is purely editorial (it just changes notes, nothing normative), it would be considered implemented in any clang version?

https://github.com/llvm/llvm-project/pull/100747