Revert "RegExp: Add support for the ES6-proposed sticky flag"

Causes a flaky failure on buildbots. Here is the (deterministic) repro step (thanks to Michael Stanton):

first go to flag-definitions.h and set this to false.

DEFINE_BOOL(enable_sse4_1, false,
            "enable use of SSE4.1 instructions if available")

Run the following and it should fail:

tools/run-tests.py --arch=ia32 --mode=release cctest/test-api/Regress2107

R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/580123002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24045 ce2b1a6d-e550-0410-aec6-3dcde31c8c00