Also change UINT32_MAX in <stdint.h> from 4294967295 to 4294967295U.
The U suffix avoids a promotion to long or unsigned long if it would
fit in unsigned int.
Define _EM_LLSIZE but not EM_LLSIZE. The leading underscore is a
convention for such macros. If code always uses _EM_LLSIZE, we will
never need to add EM_LLSIZE. The flag -D_EM_LLSIZE={q} is in
plat/linux386/descr, not lib/descr/fe, so platforms without long long
don't define _EM_LLSIZE.
<stdint.h> doesn't keep the old code for _EM_LSIZE == 8, because I
change it to _EM_LLSIZE == 8. No platform had _EM_LSIZE == 8, and the
old limits like INT64_MAX were wrong.
