LibJS: Add object literal method shorthand

Libraries/LibJS/Tests/object-method-shorthand.js

@@ -0,0 +1,29 @@
+load("test-common.js");
+
+try {
+    const o = {
+        foo: "bar",
+        getFoo() {
+            return this.foo;
+        },
+        12() {
+            return this.getFoo();
+        },
+        "hello friends"() {
+            return this.getFoo();
+        },
+        [4 + 10]() {
+            return this.getFoo();
+        },
+    };
+
+    assert(o.foo === "bar");
+    assert(o.getFoo() === "bar");
+    assert(o[12]() === "bar");
+    assert(o["hello friends"]() === "bar");
+    assert(o[14]() === "bar");
+
+    console.log("PASS");
+} catch (e) {
+    console.log("FAIL: " + e);
+}