Version 3.20.14.1: Rollback of r16071 in trunk branch.

Un-revert "Implement simple effect typing for variables" and "Handle switch effects"

R=dslomov@chromium.org

Review URL: https://codereview.chromium.org/22546003

git-svn-id: https://v8.googlecode.com/svn/trunk@16096 ce2b1a6d-e550-0410-aec6-3dcde31c8c00