Instead of testing the value of a constant frame element to determine
the type we compute its type information at construction time.

This speeds up querying the type information during code generation.

This change also adds support for Integer32 constants and sets 
the type information accordingly.

Review URL: http://codereview.chromium.org/1277001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4256 ce2b1a6d-e550-0410-aec6-3dcde31c8c00