Port r198088 (set NO_DEAD_STRIP for clang) from make to cmake. Also stop setting passing -dead_strip explicitly for libclang and instead rely on this now happening by default. (And make it happen by default for add_clang_library, which doesn't use the library cmake functions from llvm.) llvm-svn: 198200 GitOrigin-RevId: 194c00935263e88e3222a531ba1f3f2570b06eb3