With this CL, we devolve all Constants introduced as they are with an object handle into

* Range - for integers
* Nan
* MinusZero
* OtherNumberConstant - for doubles
* HeapConstant

We reduce the amount we have to inspect an object handle during optimization. Also, simplifications result. For example, you never have to check if a Range contains a HeapConstant.

BUG=

Review-Url: https://codereview.chromium.org/2381523002
Cr-Commit-Position: refs/heads/master@{#40041}