For compatibility with linkers that don't yet understand soft
permutations, don't add a ":0" to the strong name of soft
permutation number 0.

Review at http://gwt-code-reviews.appspot.com/353801

Review by: jat@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@7925 8db76d5a-ed1c-0410-87a9-c151d255dfc7