[clang] [Clang][CodeGen] Automatically resolve MSVC _hypotf and dllimport for… (PR #207135)

[Junji Watanabe via cfe-commits]

Jwata wrote:

> @Jwata made #209403 instead of this.

Actually, I got a feedback in the PR that this is a clang issue. To be honest, I'm not really sure which layer this issue should be fixed. 

https://github.com/llvm/llvm-project/pull/207135