[clang] [Clang] Add __has_target_builtin macro (PR #126324)

[Andrew Pinski via cfe-commits]

pinskia wrote:

Maybe the problem with the name I am having is the word `has`. Maybe `__can_use_builtin` seems like a better name. And that seems like would be a good context sensative clue.

https://github.com/llvm/llvm-project/pull/126324