[CMake] Fix install for macOS toolchain
recursive-lipo requires shared libraries have +x permissions.
Use PROGRAMS instead of FILES when installing swift-syntax libraries.
(cherry picked from commit 319b8bd691d25c0a52664002efad268eec944cff)
(cherry picked from commit 5bbab90c2662d5cb7bac2af469fb2bb8275531bd)
