[libc-dev] `ninja check-libc` : target does not exist on Windows

[Mehdi AMINI via libc-dev]

Hi,

We configured Phabricator pre-merge testing to be more fine grain in
selecting the tests to run.
As such when a patch touches libc, it'll try to run `ninja check-libc`
instead of `check-all`. This works well on linux, but somehow it does
not on Windows.

Here is one log for example:
https://buildkite.com/llvm-project/premerge-checks/builds/58009

The libc project is correctly enabled in CMake:

-- libc project is enabled

But then it fails with:

ninja: error: unknown target 'check-libc', did you mean 'check-lit'?


Does anyone know why? I can find anything Windows specific in the
various CMakeLists.txt in the libc folder of the repo.

thanks,

-- 
Mehdi