Migrated several tests from blink to V8 repository.

test/webkit/regexp-backreferences.js

Index: test/webkit/regexp-backreferences.js
diff --git a/test/webkit/concat-while-having-a-bad-time.js b/test/webkit/regexp-backreferences.js
similarity index 69%
copy from test/webkit/concat-while-having-a-bad-time.js
copy to test/webkit/regexp-backreferences.js
index dfda1e08a0b36194b787a44ee12a9693acd8aeaf..58db01232830c47449bcd2995804e061080942aa 100644
--- a/test/webkit/concat-while-having-a-bad-time.js
+++ b/test/webkit/regexp-backreferences.js
@@ -21,11 +21,20 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-description(
-"Tests the behavior of Array.prototype.concat while the array is having a bad time due to one of the elements we are concatenating."
-);
+description("Test to ensure correct behaviour when using backreferences in a RegExp");
 
-Object.defineProperty(Array.prototype, 0, { writable: false });
-shouldBe("[42].concat()", "[42]");
+shouldBeTrue("/(...)\\1$/.test('abcabc')");
+shouldBeFalse("/(...)\\1$/.test('abcdef')");
+shouldBeFalse("/(...)\\2$/.test('abcabc')");
+shouldBeFalse("/(...)\\2$/.test('abc')");
+shouldBeTrue("/\\1(...)$/.test('abcabc')");
+shouldBeTrue("/\\1(...)$/.test('abcdef')");
+shouldBeFalse("/\\2(...)$/.test('abcabc')");
+shouldBeFalse("/\\2(...)$/.test('abc')");
+shouldBeTrue("/\\1?(...)$/.test('abc')");
+shouldBeTrue("/\\1?(...)$/.test('abc')");
 
+re = new RegExp("[^b]*((..)|(\\2))+Sz", "i");
 
+shouldBeFalse("re.test('axabcd')");
+shouldBeTrue("re.test('axabcsz')");