Fixes a bug in SerializableTypeOracleBuilder where multi-dimensional
array types might not also pull in array types with lower rank.
A fast path was not computing complete information.

Review by: fabbott


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@5982 8db76d5a-ed1c-0410-87a9-c151d255dfc7