crossgcc: Add buildgcc support for Apple M1/M2 devices

GMP and IASL don't compile with the default compiler and linker flags:
- GMP's check for the MacOS architecture hard coded x86_64 but it also
  needs to know about arm64.
- iasl does some trickery on pointer alignment to save space(?), so we
  need to tell clang about it.

Change-Id: If4cca9d3e55051a6121d992e5320bee1df17af9f
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80435
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/crossgcc/buildgcc

@@ -847,10 +847,11 @@ build_IASL() {
 	cd ../$IASL_DIR/generate/unix || exit 1
 	CFLAGS="$HOSTCFLAGS"
 	HOST="_LINUX"
-	test "$UNAME" = "Darwin" && HOST="_APPLE"
+	test "$UNAME" = "Darwin" && HOST="_APPLE" && OPT_LDFLAGS="-Wl,-no_fixup_chains"
 	test "$UNAME" = "FreeBSD" && HOST="_FreeBSD"
 	test "$UNAME" = "Cygwin" && HOST="_CYGWIN"
 	HOST="$HOST" CFLAGS="$CFLAGS" \
+	OPT_LDFLAGS="$OPT_LDFLAGS" \
 	OPT_CFLAGS="-O -D_FORTIFY_SOURCE=2 -D COREBOOT_TOOLCHAIN_VERSION='\"coreboot toolchain v$CROSSGCC_VERSION\"' " \
 	$MAKE $JOBS CC="$(hostcc host)" iasl acpibin acpidump acpiexec acpihelp acpisrc acpixtract
 	mkdir -p "$DESTDIR$TARGETDIR/bin/"
@@ -1143,6 +1144,8 @@ if [ "$UNAME" = "Darwin" ]; then
 	# so we're setting the ABI explicitly here.
 	if [ "$(sysctl -n hw.optional.x86_64 2>/dev/null)" -eq 1 ] 2>/dev/null; then
 		OPTIONS="ABI=64"
+	elif [ "$(sysctl -n hw.optional.arm64 2>/dev/null)" -eq 1 ] 2>/dev/null; then
+		OPTIONS="ABI=64"
 	else
 		OPTIONS="ABI=32"
 	fi