X87: Only create arguments-maps in the bootstrapper, remove now obsolete ValueType flag.

port r22245.

orginal commit message:

  Only create arguments-maps in the bootstrapper, remove now obsolete ValueType flag.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/372123004

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

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22260 ce2b1a6d-e550-0410-aec6-3dcde31c8c00