build: OS X 64-bit build

R=rsc
http://codereview.appspot.com/4838047

bin/9a

@@ -5,10 +5,16 @@ if [ $# != 1 ]; then
 	exit 1
 fi
 
+test -f $PLAN9/config && . $PLAN9/config
+
 aflags=""
-case "`uname`" in
-Darwin)
-	aflags="-arch `arch`"
+case "`uname`-${OBJTYPE:-`uname -m`}" in
+Darwin-*386*)
+	aflags="-arch i386"
+	;;
+Darwin-*x86_64*)
+	aflags="-arch x86_64"
+	;;
 esac
 
 out=`echo $1 | sed 's/\.s$//;s/$/.o/'`

bin/9c

@@ -70,6 +70,8 @@ case "$tag" in
 *FreeBSD*gcc*)	usegcc ;;
 *FreeBSD*clang*)	useclang ;;
 *BSD*)	usegcc ;;
+*Darwin-x86_64*) usegcc
+		cflags="$ngflags -g3 -no-cpp-precomp -m64" ;;
 *Darwin*)	usegcc 
 		cflags="$ngflags -g3 -no-cpp-precomp -m32" ;;
 *HP-UX*)	cc=${CC9:-cc}; cflags="-g -O -c -Ae" ;;

bin/9l

@@ -45,6 +45,9 @@ case "$tag" in
 		;;
 	esac
 	;;
+*Darwin*x86_64*)
+	ld="${CC9:-gcc} -m64"
+	;;
 *Darwin*)
 	ld="${CC9:-gcc} -m32"
 	;;