[libc-commits] [libc] [libc][POSIX] Add clock_settime() function (PR #161729)

[Anton Shepelev via libc-commits]

amemov wrote:

Here are some questions that popped up when I started working on my PR:
- When I was looking at the `clock_gettime` implementation, I saw that it is implemented for GPUs, but in [`time.rst`](https://github.com/llvm/llvm-project/blob/4e404d0e5135ae7d0d4e7cc4c9b04d456eb50a01/libc/docs/headers/time.rst) file it is not marked as check. Is it correct or I should change that in my PR?
- About testing: from my understanding to call `clock_settime()` and actually change the time succesfully, a caller needs to have appropriate permission. How to emulate this in tests or it can be ignored? 

https://github.com/llvm/llvm-project/pull/161729