LibJS: Implement most of the Reflect object

Libraries/LibJS/Tests/Reflect.apply.js

@@ -0,0 +1,37 @@
+load("test-common.js");
+
+try {
+    assert(Reflect.apply.length === 3);
+
+    [null, undefined, "foo", 123, NaN, Infinity].forEach(value => {
+        assertThrowsError(() => {
+            Reflect.apply(value);
+        }, {
+            error: TypeError,
+            message: "First argument of Reflect.apply() must be a function"
+        });
+
+        assertThrowsError(() => {
+            Reflect.apply(() => {}, undefined, value);
+        }, {
+            error: TypeError,
+            message: "Arguments list must be an object"
+        });
+    });
+
+    assert(Reflect.apply(String.prototype.charAt, "foo", [0]) === "f");
+    assert(Reflect.apply(Array.prototype.indexOf, ["hello", 123, "foo", "bar"], ["foo"]) === 2);
+
+    function Foo(foo) {
+        this.foo = foo;
+    }
+
+    var o = {};
+    assert(o.foo === undefined);
+    assert(Reflect.apply(Foo, o, ["bar"]) === undefined);
+    assert(o.foo === "bar");
+
+    console.log("PASS");
+} catch (e) {
+    console.log("FAIL: " + e);
+}