Slightly improved Hydrogen stats output for long-running compilations.

Replaced a scary pointer comparison by strcmp on the way.

Review URL: https://codereview.chromium.org/12035101

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13510 ce2b1a6d-e550-0410-aec6-3dcde31c8c00