Added fast-case for switch statement where all lables are constant Smi's in a limited range (IA32 only so far).
Implemented using a jump-table, for constant time lookup.


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@343 ce2b1a6d-e550-0410-aec6-3dcde31c8c00