[libc-commits] [libc] [libc][tsearch] add tsearch functions (PR #172625)

[Schrodinger ZHU Yifan via libc-commits]

SchrodingerZhu wrote:

@michaelrj-google I have rebased the code onto its merged stack parent. PTAL.

One special place to pay additional attention to is the `__llvm_posix_tnode`. I am not very certain about the design. If you think this compatibility layer is not required, I can remove it.

https://github.com/llvm/llvm-project/pull/172625