Migrated several tests from blink to V8 repository.

test/webkit/dfg-constant-fold-first-local-read-after-block-merge.js

Index: test/webkit/dfg-constant-fold-first-local-read-after-block-merge.js
diff --git a/test/webkit/concat-while-having-a-bad-time.js b/test/webkit/dfg-constant-fold-first-local-read-after-block-merge.js
similarity index 74%
copy from test/webkit/concat-while-having-a-bad-time.js
copy to test/webkit/dfg-constant-fold-first-local-read-after-block-merge.js
index dfda1e08a0b36194b787a44ee12a9693acd8aeaf..396924240d4120ac1b069c7bc17bdc0593549ea4 100644
--- a/test/webkit/concat-while-having-a-bad-time.js
+++ b/test/webkit/dfg-constant-fold-first-local-read-after-block-merge.js
@@ -22,10 +22,26 @@
 // 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 the DFG doesn't crash if we constant fold the first read of a local variable in a block that is the result of merging two blocks, where the first doesn't touch the local and the second reads it."
 );
 
-Object.defineProperty(Array.prototype, 0, { writable: false });
-shouldBe("[42].concat()", "[42]");
+function foo(x, y) {
+    var o = {};
+    if (y == 5) {
+        o.f = 42;
+    }
+    var z = o.f;
+    if (x == 5) {
+        if (y == 5) {
+            return z;
+        }
+    }
+}
 
+function bar(x) {
+    return foo(x, 5);
+}
+
+for (var i = 0; i < 200; ++i)
+    shouldBe("bar(5)", "42");