Make `String.prototype.contains` throw when passing a regular expression

Contributed by Mathias Bynens <mathiasb@opera.com>.

TEST=mjsunit/harmony
BUG=v8:3261
LOG=Y
R=yangguo@chromium.org, arv@chromium.org, ishell@chromium.org

Review URL: https://codereview.chromium.org/227113005

Patch from Mathias Bynens <mathiasb@opera.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20534 ce2b1a6d-e550-0410-aec6-3dcde31c8c00