port r22448

original commit message:
  StubCallInterfaceDescriptor and CallInterfaceDescriptor are unified under a base class InterfaceDescriptor.

  Handling of the context register had to be massaged to effect the unification. This will make it easier
  to call hydrogen code stubs directly from crankshaft.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/399313005

Patch from Chunyang Dai <chunyang.dai@intel.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22459 ce2b1a6d-e550-0410-aec6-3dcde31c8c00