[libcxx-commits] [libcxx] [libcxxabi] [libc++] Simplify how we install test-suite dependencies (PR #171504)

[Alexander Richardson via libcxx-commits]

arichardson wrote:

> > Looks much simpler. Nice! Not tested it locally but lgtm assuming the tests pass
> 
> I think I am running into race conditions between the install targets in the CI. I may have to artificially serialize these installations, which IMO is OK.

Does that mean we have multiple install steps trying to write the same file? The one CI failure I see is
```
  -- Set runtime path of "/home/gha/actions-runner/_work/llvm-project/llvm-project/build/generic-gcc/libcxx/test-suite-install/lib/libc++.so.1.0" to ""
  CMake Error at /home/gha/actions-runner/_work/llvm-project/llvm-project/build/generic-gcc/libcxx/src/cmake_install.cmake:103 (file):
    file INSTALL cannot find
    "/home/gha/actions-runner/_work/llvm-project/llvm-project/build/generic-gcc/lib/libc++experimental.a":
```

This suggests to me that we are just missing a dependency somewhere?

https://github.com/llvm/llvm-project/pull/171504