Fix the invalid array length check, replacing it with a check of
the elements pointer similar to TransitionElementsKindStub.
Refactor common code from ElementsTransitionAndStoreStub and TransitionElementsKindStub into BuildTransitionElementsKind() helper method.
Add test case for the MD5 computation that used to crash before,
and a small test case for the specific issue.

R=danno@chromium.org

Review URL: https://codereview.chromium.org/19367003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15713 ce2b1a6d-e550-0410-aec6-3dcde31c8c00