Some MIPS boards could not handle the large number of threads and failed these tests.

BUG=
TEST=
Review URL: http://codereview.chromium.org/8506008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10048 ce2b1a6d-e550-0410-aec6-3dcde31c8c00