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

[Mital Ashok via cfe-commits]

MitalAshok wrote:

New test compiles down to clang 3.0 (except warnings for https://cplusplus.github.io/CWG/issues/547.html) but do not compile before that because of the lack of `__is_const`/`__is_volatile` type traits.

Function types with cv- qualifiers were added for Clang 2.5 in 22c40fa28551f0da487f399a2fe0d3d25edf3edc, where they already used a different field to hold the qualifiers (thus the function types were not considered `const`/`volatile`/`__restrict` themselves), so it should be okay to claim this was implemented in Clang 2.5?

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