MIPS: Utility functions for pretenure call new.

Port r19998 (6b07a42)

Original commit message:
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.

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/196423018

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20014 ce2b1a6d-e550-0410-aec6-3dcde31c8c00