x32: add ia32 support

x32: add ia32 support

* Makefile.am (EXTRA_DIST): Add linux/x32/errnoent1.h,
linux/x32/ioctlent1.h, linux/x32/signalent1.h and
linux/x32/syscallent1.h.
* configure.ac: Remove AC_GNU_SOURCE, obsoleted by
AC_USE_SYSTEM_EXTENSIONS.
* defs.h (SUPPORTED_PERSONALITIES): Set to 2 for X32.
(PERSONALITY1_WORDSIZE): Set to 4 for X32.
* file.c (stat64): New struct for X32.
(sys_lseek32): New function for X32.
(stat64): Undef.
(sys_fstat64): Likewise.
(sys_stat64): Likewise.
(realprintstat64): New function for X32.
(sys_fstat64): Likewise.
(sys_stat64): Likewise.
* mem.c (sys_old_mmap): New function for X32.
* pathtrace.c (pathtrace_match): Also check sys_old_mmap for X32.
* syscall.c (update_personality): Add X32 support.
(get_scno): Support currpers == 1 for X32.
* linux/syscall.h (sys_lseek32): New function prototype for X32.
* linux/x32/errnoent1.h: New file.
* linux/x32/ioctlent1.h: Likewise.
* linux/x32/signalent1.h: Likewise.
* linux/x32/syscallent1.h: Likewise.