Revert r22597 (which should have been called: "Tests that the GC doesn't mistake non-pointer constant pool entries as poitners.")

TBR=yangguo@chromium.org

Review URL: https://codereview.chromium.org/413173002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22598 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
SKIP migration tests to improve unit test time (2x)

R=ishell@chromium.org

Review URL: https://codereview.chromium.org/416003004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22599 ce2b1a6d-e550-0410-aec6-3dcde31c8c00