Fixes ICE involving JDT-unreachable local types.

Fixes: http://code.google.com/p/google-web-toolkit/issues/detail?id=5552
Review at: http://gwt-code-reviews.appspot.com/1083801/show

Review by: cromwellian@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@9200 8db76d5a-ed1c-0410-87a9-c151d255dfc7