Split CompileCallConstant into logical parts for Frontend and Backend.

Initial step towards separating IC (map check(s)), handler frontend
(prototype-check) and handler backend (actual handler code).

- Still need to split the map-check (IC) from rest of the prototype
  chain check.
- Still need to turn different parts in own code objects and cache them
  in more optimal places.

Review URL: https://chromiumcodereview.appspot.com/12207016

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13604 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Small improvement in x64 assembler

Review URL: https://chromiumcodereview.appspot.com/12177012
Patch from Zheng Z. Liu <zheng.z.liu@intel.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13605 ce2b1a6d-e550-0410-aec6-3dcde31c8c00