Fix --hydrogen-stats.

V8 crashes with this flag when trying to compile hydrogen stubs.

R=jkummerow@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/12045048

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13487 ce2b1a6d-e550-0410-aec6-3dcde31c8c00