bug#9713: emacs 24.0.90 alloc.c assertion failure

[Glenn Morris]

FWIW, I had no problems compiling on x86_64 Scientific Linux 5.7 (which
should be identical to CentOS 5.7 for almost all purposes) using either
the default "gcc 4.1.2 20080704 (Red Hat 4.1.2-51)", or the optional
gcc44 package, which provides "gcc44 (GCC) 4.4.4 20100726 (Red Hat 4.4.4-13)".

The system has

limits.h:
# define INT_MAX      2147483647

stdint.h:
# if __WORDSIZE == 64
#  define PTRDIFF_MIN       (-9223372036854775807L-1)
#  define PTRDIFF_MAX           (9223372036854775807L)
# else
#  define PTRDIFF_MIN       (-2147483647-1)
#  define PTRDIFF_MAX           (2147483647)
# endif