[llvm] r309310 - Un-revert "Teach the CMake build system to run lit's test suite. These can be run"

[Brian Gesiak via llvm-commits]

Douglas,

Thanks for the heads up, and thank you for investigating the cause of
the buildbot failures. I think you're correct, FileCheck must not be
getting picked up by lit. Normally lit.cfg adds the LLVM binary tools
directory to the PATH before executing tests [1]. It must be failing
to do so for Visual Studio builds.

If I recall, about a year ago I built FileCheck using Visual Studio,
and the executable was placed in '<build directory>/Debug/bin',
instead of '<build directory>/bin', which is where Ninja places it.
Perhaps this is related? I'll investigate the issue.

Unfortunately it takes me several hours to build using Visual Studio
on my Windows machine. I'll try to send a fix as soon as possible, but
if you have a faster development environment I'd also appreciate your
help! Sorry for the inconvenience.

[1] https://github.com/llvm-mirror/llvm/blob/0bc57f232fe522fce813b8379ccbe9ffbd9c7550/test/lit.cfg#L60-L66

- Brian Gesiak