Remove --harmony implications for incomplete features
This is in preparation for making --harmony and --es-staging synonyms.
The only remaining difference currently is block-scoping, which is still
implied by --harmony, to avoid regressing on a long-available feature.
Also removes the special-casing of --harmony-proxies.
R=adamk@chromium.org
BUG=
Review URL: https://codereview.chromium.org/
693153004
Cr-Commit-Position: refs/heads/master@{#25115}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25115
ce2b1a6d-e550-0410-aec6-
3dcde31c8c00