X87: Drop unnecessary receiver validity checks from {Load,Store}IC_Normal

X87: Drop unnecessary receiver validity checks from {Load,Store}IC_Normal

port r22391

original commit message:
   Drop unnecessary receiver validity checks from {Load,Store}IC_Normal.

   Since these builtins are used as handlers after a map check/dispatch, they don't need to check the receiver again.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/396833004

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

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22416 ce2b1a6d-e550-0410-aec6-3dcde31c8c00