[libcxx-commits] [libcxx] [libc++] Add a utility for checking the output of commands (PR #65917)

[Louis Dionne via libcxx-commits]

ldionne wrote:

Closing per discussion with Nikolas since we will most likely pursue installing `FileCheck` in the test suite instead. This can always be reopened if needed.

https://github.com/llvm/llvm-project/pull/65917