[compiler-rt] [compiler-rt] Allow running tests without installing first (PR #83088)

[Jan Patrick Lehr via llvm-commits]

jplehr wrote:

Hi. This may have caused a breakage on one of our buildbots https://lab.llvm.org/buildbot/#/builders/165/builds/51837
Let me know if you need some assistance.

https://github.com/llvm/llvm-project/pull/83088