[compiler-rt] [compiler-rt] Propagate sysroot from CMake to msan tests (PR #132299)

[Vitaly Buka via llvm-commits]

https://github.com/vitalybuka approved this pull request.

if it's good enough @petrhosek, then it's good enough for me. LGTM

https://github.com/llvm/llvm-project/pull/132299