Utility functions for pretenure call new. These functions aren't yet called in the tree but will be in the next days. AssertUndefinedOrAllocationSite is to be used in several places where AllocationSite feedback is optional.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/197643008

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19998 ce2b1a6d-e550-0410-aec6-3dcde31c8c00