For example, invalid left hand sides are reference errors. PreParser didn't use
to produce this error ever, so the code for propagating reference errors
properly was missing, and reference errors turned into syntax errors.

R=rossberg@chromium.org
BUG=

Review URL: https://codereview.chromium.org/220233006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20408 ce2b1a6d-e550-0410-aec6-3dcde31c8c00