Remove benchmark runner.

This has been renamed to run_perf.

BUG=374740
LOG=n
TBR=dslomov@chromium.org

Review URL: https://codereview.chromium.org/564373003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23942 ce2b1a6d-e550-0410-aec6-3dcde31c8c00