Include of <sys/user.h> in bfd/trad-core.c can set NBPG to PAGE_SIZE which causes a build failure with some configs

[Stephen M. Kenton]

Include of <sys/user.h> in bfd/trad-core.c can set NBPG to PAGE_SIZE 
which causes a build failure with some configs. An undef statement got 
things building for me again with binutils-2.18.50.  Is there some 
reason this is not unconditional now that PAGE_SIZE has gone away in the 
kernel headers?

#include <signal.h>

#include <sys/user.h>           /* After a.out.h  */
#undef NBPG /* Do not let <sys/user.h> set this to PAGE_SIZE */ <---------

#ifdef TRAD_HEADER
#include TRAD_HEADER
#endif

#ifndef NBPG
# define NBPG getpagesize()
#endif

FYI - Steve Kenton