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

[Vitaly Buka via llvm-commits]

vitalybuka wrote:

Build bot still uses '-DLLVM_ENABLE_PROJECTS=clang;lld;clang-tools-extra;compiler-rt' 

can be updated here https://github.com/llvm/llvm-zorg/blob/3ed3d915a9d4de7967dd20a35a9a266b09cdba86/zorg/buildbot/builders/annotated/hip-build.sh#L4

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