The relevant part of the output of configure on x86:

checking size of int... 4
checking size of long... 4
checking size of void *... 4
checking size of short... 2
checking size of float... 4
checking size of double... 8
checking size of fpos_t... 4
checking size of size_t... 4
checking size of pid_t... 4
checking for long long support... yes
checking size of long long... 8
checking for long double support... yes
checking size of long double... 8
checking for _Bool support... yes
checking size of _Bool... 1
checking for uintptr_t... yes
checking size of uintptr_t... 4
checking size of off_t... 4
checking whether to enable large file support... no

And as a consequence in pyconfig.h:
/* Defined to enable large file support when an off_t is bigger than a long
   and long long is available and at least as big as an off_t. You may need to
   add some flags for configuration and compilation to enable this mode. (For
   Solaris and Linux, the necessary defines are already defined.) */
/* #undef HAVE_LARGEFILE_SUPPORT */