Improve representation inference

Improve representation inference

- Extend HValue interface to allow splitting observed input representation (comming from type feedback) from required input representation (dictated by instruction itself). Currently all instructions except for bitwise binary operations have this representations match. For bitwise binary operations hydrogen builder unconditionaly forces Integer32 representation for those operations that have Double type feedback. Thus causing representation inference to incorrectly count such uses as Integer32 instead of Double. This change also prepares for more fine grained type feedback for inputs of binary operations.

- For phies that are not convertable to Integer32 discard direct and indirect use count of Integer32 type to avoid propagation of these uses to connected phies.

R=jkummerow@chromium.org
BUG=v8:2096

Review URL: https://chromiumcodereview.appspot.com/10540049

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11737 ce2b1a6d-e550-0410-aec6-3dcde31c8c00