Simplify public pipeline interface.

R=sigurds@chromium.org

Review URL: https://codereview.chromium.org/471563002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23106 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Move %IsOptimized runtime helper into test case.

R=jarin@chromium.org
TEST=cctest/test-run-deopt

Review URL: https://codereview.chromium.org/468153002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23107 ce2b1a6d-e550-0410-aec6-3dcde31c8c00