[clang] [llvm] [clang] Reland Add tanf16 builtin and support for tan constrained intrinsic (PR #94559)

[David Green via cfe-commits]

davemgreen wrote:

I believe they were added so long ago that the default Expanding wasn't done at the time. @efriedma-quic do you have more of an idea than that?

https://github.com/llvm/llvm-project/pull/94559