RFR: 8066757 Can't build 'images' with --disable-zip-debug-info on OS X after jigsaw m2 merge

[Staffan Larsen]

Please review this fix for using --disable-zip-debug-info when compiling the images target.

OS X stores symbol information in a .dylib file inside a .dSYM directory and that file should not be stripped, so this patch prunes the tree at the .dSYM directory.

bug: https://bugs.openjdk.java.net/browse/JDK-8066757
webrev: http://cr.openjdk.java.net/~sla/8066757/webrev.00 <http://cr.openjdk.java.net/~sla/8066757/webrev.00>

Thanks,
/Staffan