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.

bin/package

@@ -2396,7 +2396,10 @@ int main()
 			case $lhs in
 			bsdi)			lhs=bsd ;;
 			darwin)			case $(/usr/bin/cc --version) in
-						*'(GCC)'*)	lhs=${lhs}_old ;;
+						*'(GCC)'*)	case $rel in
+								[0-9].*|10.*)	lhs=darwin07 ;;
+								*)		lhs=darwin11 ;;
+								esac ;;
 						esac
 						;;
 			freebsd)		case $rel in