Bug 989204 part 1 - Add some arrow function tests. r=jorendorff

--HG--
extra : rebase_source : 0b3c9ddd82621fd76e7d48559f339cdea6c40a76

js/src/jit-test/tests/arrow-functions/bug889158.js

@@ -0,0 +1,4 @@
+var f = x => arguments.callee;
+
+for (var i=0; i<5; i++)
+    assertEq(f(), f);

js/src/jit-test/tests/arrow-functions/this-5.js

@@ -0,0 +1,12 @@
+// Arrow functions can have primitive |this| values.
+
+Number.prototype.foo = function() {
+    "use strict";
+    return () => this;
+}
+
+for (var i=0; i<5; i++) {
+    var n = i.foo()();
+    assertEq(typeof n, "number");
+    assertEq(n, i);
+}

js/src/jit-test/tests/arrow-functions/this-6.js

@@ -0,0 +1,11 @@
+// Eval expressions in arrow functions use the correct |this| value.
+
+function Dog(name) {
+    this.name = name;
+    this.getName = () => eval("this.name");
+    this.getNameHard = () => eval("(() => this.name)()");
+}
+
+var d = new Dog("Max");
+assertEq(d.getName(), d.name);
+assertEq(d.getNameHard(), d.name);