X87: Implement inline %_IsJSProxy() for full codegen and Hydrogen.

port r24636.

original commit message:

  Implement inline %_IsJSProxy() for full codegen and Hydrogen
  Saving a runtime call for many builtin functions.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/657273002

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

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24649 ce2b1a6d-e550-0410-aec6-3dcde31c8c00