[libclang] Check LLVM_HAVE_LINK_VERSION_SCRIPT

There are some platform that might not have version script support,
don't try to use version script on those.

Reviewed By: MaskRay, hubert.reinterpretcast

Differential Revision: https://reviews.llvm.org/D106914

GitOrigin-RevId: e07f9342be7132f433963880d95e471ae2246d64
1 file changed