When the regexp pattern parser encounters an unbound reference to a
capturing group, it needs to scan ahead to decide whether it really
is a reference.  The scan advances to the end of the pattern string
and sets has_more_ to false, but fails to reset it to true so that
later on, parsing a character class wrongly fails.

R=ulan@chromium.org
BUG=v8:2690

Review URL: https://chromiumcodereview.appspot.com/15712006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14817 ce2b1a6d-e550-0410-aec6-3dcde31c8c00