Fix glibc specific conditional for Mac OS/X
MacOS seems to define __GLIBC__ but not __GLIBC_PREREQ.
@@ -231,7 +231,8 @@ static uint64_t get_timer_bits(void)
# if defined(_POSIX_C_SOURCE) \
&& defined(_POSIX_TIMERS) \
&& _POSIX_C_SOURCE >= 199309L \
- && (!defined(__GLIBC__) || __GLIBC_PREREQ(2, 17))
+ && (!defined(__GLIBC__) \
+ || (defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 17)))
{
struct timespec ts;
clockid_t cid;
