Migrated several tests from blink to V8 repository.

test/webkit/dfg-dead-unreachable-code-with-chain-of-dead-unchecked-nodes.js

Index: test/webkit/dfg-dead-unreachable-code-with-chain-of-dead-unchecked-nodes.js
diff --git a/test/webkit/concat-while-having-a-bad-time.js b/test/webkit/dfg-dead-unreachable-code-with-chain-of-dead-unchecked-nodes.js
similarity index 72%
copy from test/webkit/concat-while-having-a-bad-time.js
copy to test/webkit/dfg-dead-unreachable-code-with-chain-of-dead-unchecked-nodes.js
index dfda1e08a0b36194b787a44ee12a9693acd8aeaf..bded985dda65601cd1ca6499595e8a897f72a1ef 100644
--- a/test/webkit/concat-while-having-a-bad-time.js
+++ b/test/webkit/dfg-dead-unreachable-code-with-chain-of-dead-unchecked-nodes.js
@@ -22,10 +22,19 @@
 // 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."
+"Tests that code that is dead, unreachable, and contains a chain of nodes that use each other in an untyped way doesn't result in the IR getting corrupted."
 );
 
-Object.defineProperty(Array.prototype, 0, { writable: false });
-shouldBe("[42].concat()", "[42]");
-
+function foo(a) {
+    function bar(p) {
+        if (p) {
+            var x = a; // It's dead and unreachable, and it involves a GetScopeVar(GetScopeRegisters(GetMyScope())).
+        }
+        return 5;
+    }
+    return bar;
+}
 
+// Since the function contains unreachable code we need a higher optimization threshold.
+for (var i = 0; i < 1000; ++i)
+    shouldBe("foo(42)(false)", "5");