__glibc_has_builtin   52 lib/cdefs.h    # define __glibc_has_builtin(name) __has_builtin (name)
__glibc_has_builtin   54 lib/cdefs.h    # define __glibc_has_builtin(name) 0
__glibc_has_builtin  149 lib/libc-config.h # undef __glibc_has_builtin