Fix __cfi_check not aligned to 4k on relocatable files with no executable code

CrossDSOCFIPass is supposed to replace this stub function to a properly
aligned function. However the pass is not ran if the file has no
executable code, thus producing incorrectly aligned __cfi_check.

Fixes https://github.com/llvm/llvm-project/issues/45638.

Differential Revision: https://reviews.llvm.org/D155736