[compiler-rt] [llvm] [compiler-rt] Add check-builtins target for LLVM_ENABLE_RUNTIMES builds (PR #166837)

[Andrew Haberlandt via llvm-commits]

ndrewh wrote:

@petrhosek  My guess: It's this extra `.*hf` renaming logic that is present in `compiler-rt/CMakeLists.txt` but not in `compiler-rt/lib/builtins/CMakeLists.txt`. So the runtimes build (which has `check-builtins`) gets a rename that `compiler-rt/lib/builtins/CMakeLists.txt` does not...

https://github.com/llvm/llvm-project/blob/58c8f5768102751ce932b597563aaa4a3b7fa430/compiler-rt/CMakeLists.txt#L149-L159
https://github.com/llvm/llvm-project/blob/3e16aef2a650a8c2da4ebd5c58c6a9e261361828/compiler-rt/lib/builtins/CMakeLists.txt#L31-L41

I'm not sure why that isn't in some shared code like `construct_compiler_rt_default_triple`...?

https://github.com/llvm/llvm-project/pull/166837