make failed on Mac OS X including sys/random.h

It looks to be caused by this commit: https://github.com/python/cpython/commit/1958527a2c5dda766b1917ab563622434b3dad0d

Restoring the removed ifdefs solves the problem (see github PR)

Official patch to follow


Failure message.
```
In file included from Python/random.c:16:
/usr/include/sys/random.h:37:32: error: unknown type name 'u_int'
void read_random(void* buffer, u_int numBytes);
                               ^
/usr/include/sys/random.h:38:33: error: unknown type name 'u_int'
void read_frandom(void* buffer, u_int numBytes);
                                ^
/usr/include/sys/random.h:39:33: error: unknown type name 'u_int'
int  write_random(void* buffer, u_int numBytes);
                                ^
3 errors generated.
make: *** [Python/random.o] Error 1
```