Revert "Implement handling of arrow functions in the parser"

This reverts r22265.

Reason: ASAN tests fail.

BUG=
TBR=marja@chromium.org,aperez@igalia.com

Review URL: https://codereview.chromium.org/372983003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22266 ce2b1a6d-e550-0410-aec6-3dcde31c8c00