Fix compilation with Clang after r16530.

TBR=titzer@chromium.org

Review URL: https://codereview.chromium.org/23526015

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16534 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Add better consistency check and error output to plot script.

R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/23736004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16537 ce2b1a6d-e550-0410-aec6-3dcde31c8c00