[llvm] [Cygwin] Cygwin general (PR #74944)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

Changes need a more elaborate explanation than this.

We shouldn't, in general, be moving platform specific code from `Windows/Process.inc` into the comon code in `Process.cpp`. I presume the context is that Cygwin builds generally are considered Unix, not Windows, and use `Unix/Process.inc`, while for this specific function, it needs to use Win32 API. Such context needs to be mentioned for reviewers to be able to make sense of the change.

I'm not sure what the cleanest/most acceptable way to do that would be though - @MaskRay?

https://github.com/llvm/llvm-project/pull/74944