LONG_LONG_MIN/MAX: Move declarations to <limits.h>

LONG_LONG_MIN, LONG_LONG_MAX and ULONG_LONG_MAX are
GLibc-specific macros that are better defined in <limits.h>
instead of the current exotic location (<pthread.h>).

Note that GCC's <limits.h> only defines these macros
when __GNU_LIBRARY__ is also defined. This is only the
case when building against GLibc, so manually redefine
the macros here.

Note that using LLONG_MIN/LLONG_MAX/ULLONG_MAX is the
C99-compliant way to get these values, but it's easier
to define these compatibility macros for the sake of
porting existing code.

Change-Id: I8023918d73b4685238054932f94a4006c1ca7d03

libc/include/pthread.h

@@ -310,9 +310,4 @@ extern void  __pthread_cleanup_pop(__pthread_cleanup_t*  c,
 } /* extern "C" */
 #endif
 
-/************ TO FIX ************/
-
-#define LONG_LONG_MAX __LONG_LONG_MAX__
-#define LONG_LONG_MIN (-__LONG_LONG_MAX__ - 1)
-
 #endif /* _PTHREAD_H_ */