Prevent interference of allocation sites with array-natives-elements test.

This should make the arm64 build green again.

R=mvstanton@chromium.org
BUG=

Review URL: https://codereview.chromium.org/285663005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21288 ce2b1a6d-e550-0410-aec6-3dcde31c8c00