MIPS: Bugfix: array constructors that expect a type feedback cell that points to an AllocationSite were being passed the undefined object in some cases. Clearly separate the cases where we have an AllocationSite and where we don't in the general ArrayConstructorStub.

Port r16693 (0852d4ab)

BUG=
R=gergely@homejinni.com

Review URL: https://codereview.chromium.org/23451057

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16698 ce2b1a6d-e550-0410-aec6-3dcde31c8c00