Build on more darwin/macOS versions

src/cmd/INIT/cc.darwin*:
- Build on ancient Mac OS X gcc versions (darwin 7+, Mac OS X
  10.3+), more recent gcc versions (darwin 11+, Mac OS X 10.7+), as
  well as current clang versions. So there are now three cc.darwin*
  wrapper scripts for these different darwin versions.

bin/package, src/cmd/INIT/package.sh:
- Differentiate the host ID and pick the correct Darwin script based on
  the detected OS release version.

src/cmd/INIT/cc.darwin_old

@@ -1,73 +0,0 @@
-: unix wrapper for mac osx cc : 2012-01-20 :
-
-HOSTTYPE=darwin.generic
-
-case " $* " in
-*" -dumpmachine "*) echo $HOSTTYPE; exit ;;
-esac
-
-CC=/usr/bin/cc
-op=init
-for arg
-do	case $op in
-	init)	op=ld
-		set ''
-		;;
-	esac
-	case $arg in
-	-c)	op=cc
-		;;
-	-E)	op=cpp
-		continue
-		;;
-	-G)	op=dll
-		continue
-		;;
-	-lc)	continue
-		;;
-	-lm)	continue
-		;;
-	-O)	continue
-		;;
-	esac
-	set "$@" "$arg"
-done
-case $# in
-0)	;;
-*)	shift ;;
-esac
-case $* in
--v)	$CC "$@"; exit ;;
-esac
-case $op in
-init)	echo "cc: arguments expected" >&2
-	exit 1
-	;;
-cpp)	$CC -E "$@"
-	;;
-cc)	$CC -DCLK_TCK=100 "$@"
-	;;
-dll)	# what a compatibility mess -- surely they can get the apis to play nice
-	tmp=/tmp/cc.${USER:-$LOGNAME}.$$.err
-	trap "rm -f $tmp" EXIT
-	case `MACOSX_DEPLOYMENT_TARGET=10.3 ld -undefined dynamic_lookup 2>&1` in
-	*undefined*dynamic_lookup*)
-		ld -m -flat_namespace -undefined suppress -dylib -dynamic \
-			-ldylib1.o "$@" -lcc_dynamic -framework System >$tmp 2>&1
-		status=$?
-		;;
-	*)	MACOSX_DEPLOYMENT_TARGET=10.3 $CC -Wl,-flat_namespace -dynamiclib -undefined dynamic_lookup "$@" >$tmp 2>&1
-		status=$?
-		;;
-	esac
-	egrep -v ' (warning .*multiple definitions|definition) of ' $tmp >&2
-	exit $status
-	;;
-ld)	tmp=/tmp/cc.${USER:-$LOGNAME}.$$.err
-	trap "rm -f $tmp" EXIT
-	$CC -Wl,-m -DCLK_TCK=100 "$@" >$tmp 2>&1
-	status=$?
-	egrep -v ' (warning .*multiple definitions of|definition of|as lazy binding|not from earlier dynamic) ' $tmp >&2
-	exit $status
-	;;
-esac