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

[Mital Ashok via cfe-commits]

MitalAshok wrote:

> Based on https://godbolt.org/z/n6oPdMT91, I think `3.1` is the correct availability here, but I can be persuaded for `3.0`.

The warnings are because of how the test is written, the tested behaviour ("function types are never const or volatile") is still true in Clang 3.0

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