Fix InstructionSelector to handle calls with no (used) output values.

R=jarin@chromium.org
BUG=

Review URL: https://codereview.chromium.org/664693002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24689 ce2b1a6d-e550-0410-aec6-3dcde31c8c00