Migrate more tests from blink repository.

test/webkit/fast/js/regexp-look-ahead.js

Index: test/webkit/fast/js/regexp-look-ahead.js
diff --git a/test/webkit/array-tostring-and-join.js b/test/webkit/fast/js/regexp-look-ahead.js
similarity index 85%
copy from test/webkit/array-tostring-and-join.js
copy to test/webkit/fast/js/regexp-look-ahead.js
index b4fdb51b47f0b450a53fc725a133c27a21c5375d..a512e1bb2606b820d018161f2e95abdc8066b39d 100644
--- a/test/webkit/array-tostring-and-join.js
+++ b/test/webkit/fast/js/regexp-look-ahead.js
@@ -22,15 +22,8 @@
 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 description(
-
-"This test checks that toString and join share the same HashSet for visited elements."
-
+'Test for regression against <a href="https://bugs.webkit.org/show_bug.cgi?id=41458">Yarr Interpreter is crashing in some cases of look-ahead regex patterns</a>'
 );
 
-var arr = [1, 2];
-var obj = {};
-obj.__proto__.toString = function() { return "*" + arr + "*"; }
-arr[2] = arr;
-arr[3] = obj;
-
-shouldBe("arr.join()", "'1,2,,**'");
+shouldBe('"ab".match(/a(?=b|c)/)', '["a"]');
+shouldBe('"abd".match(/a(?=c|b)|d/)', '["a"]');