Partial roll-back of r2210; converting a div to a shift breaks for negative numerators.  That's what I get for not writing a unit test.

Found by: jeffreyconroy@yahoo.com



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@2295 8db76d5a-ed1c-0410-87a9-c151d255dfc7