libiberty: Disable hwcaps for sha1.o

libiberty: Disable hwcaps for sha1.o

This patch

commit bf4f40cc3195eb7b900bf5535cdba1ee51fdbb8e
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue Nov 28 13:14:05 2023 +0100

    libiberty: Use x86 HW optimized sha1

broke Solaris/x86 bootstrap with the native as:

libtool: compile:  /var/gcc/regression/master/11.4-gcc/build/./gcc/gccgo -B/var/gcc/regression/master/11.4-gcc/build/./gcc/ -B/vol/gcc/i386-pc-solaris2.11/bin/ -B/vol/gcc/i386-pc-solaris2.11/lib/ -isystem /vol/gcc/i386-pc-solaris2.11/include -isystem /vol/gcc/i386-pc-solaris2.11/sys-include -fchecking=1 -minline-all-stringops -O2 -g -I . -c -fgo-pkgpath=internal/goarch /vol/gcc/src/hg/master/local/libgo/go/internal/goarch/goarch.go zgoarch.go
ld.so.1: go1: fatal: /var/gcc/regression/master/11.4-gcc/build/gcc/go1: hardware capability (CA_SUNW_HW_2) unsupported: 0x4000000  [ SHA1 ]
gccgo: fatal error: Killed signal terminated program go1

As is already done in a couple of other similar cases, this patches
disables hwcaps support for libiberty.

Initially, this didn't work because config/hwcaps.m4 uses target_os, but
didn't ensure it is defined.

Tested on i386-pc-solaris2.11 with as and gas.

2023-11-29  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	config:
	* hwcaps.m4 (GCC_CHECK_ASSEMBLER_HWCAP): Require
	AC_CANONICAL_TARGET.

	libiberty:
	* configure.ac (GCC_CHECK_ASSEMBLER_HWCAP): Invoke.
	* configure, aclocal.m4: Regenerate.
	* Makefile.in (COMPILE.c): Add HWCAP_CFLAGS.