[clang] [llvm] [CMake] Preserve clang-prebolt (PR #109351)

[Elvina Yakubova via llvm-commits]

ElvinaYakubova wrote:

@aaupov this happens on AArch64 target, and only with -split-strategy=cdsplit enabled. Changing it to profile2, for example, fixes the issue

https://github.com/llvm/llvm-project/pull/109351