Treat PowerPC 64 LE as a separate architecture

Treat PowerPC 64 LE as a separate architecture

That seems to be the easiest way to properly handle the fact that
PPC64LE does not have a meaningful m32 personality.

* configure.ac: Move AC_C_BIGENDIAN before arch detection; determine
powerpc64/powerpc64le arch based on $ac_cv_c_bigendian value.
* linux/dummy.h [POWERPC64LE] (sys_oldselect): Redirect to printargs.
* linux/powerpc64le/arch_defs_.h: New file.
* linux/powerpc64le/arch_regs.c: Likewise.
* linux/powerpc64le/arch_rt_sigframe.c: Likewise.
* linux/powerpc64le/errnoent.h: Likewise.
* linux/powerpc64le/get_error.c: Likewise.
* linux/powerpc64le/get_scno.c: Likewise.
* linux/powerpc64le/get_syscall_args.c: Likewise.
* linux/powerpc64le/ioctls_arch0.h: Likewise.
* linux/powerpc64le/ioctls_inc0.h: Likewise.
* linux/powerpc64le/raw_syscall.h: Likewise.
* linux/powerpc64le/rt_sigframe.h: Likewise.
* linux/powerpc64le/set_error.c: Likewise.
* linux/powerpc64le/set_scno.c: Likewise.
* linux/powerpc64le/syscallent.h: Likewise.
* linux/powerpc64le/userent.h: Likewise.
* Makefile.am (EXTRA_DIST): Add them.
* tests/ipc_msg.c: Check for POWERPC64LE definition in addition to
POWERPC64.
* util.c (getllval): Add check for POWERPC64LE definition in addition to
POWERPC64.
* strace.1.in (.SH MULTIPLE PERSONALITY SUPPORT): Mention that only big
endian PowerPC 64 has mpers support.

Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>