[compiler-rt] [compiler-rt] Don't redefine LLVM_COMMON_CMAKE_UTILS if it's defined (PR #66761)

[Nikita Popov via llvm-commits]

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

LGTM, we do this everywhere else.

(I've encountered this as well, and ended up symlinking the directory to the right place. Thanks for actually fixing it...)

https://github.com/llvm/llvm-project/pull/66761