LibJS: Add the FinalizationRegistry built-in object

As well as the needed functionality in VM to enqueue and run cleanup
jobs for the FinalizationRegistry instances.

Userland/Libraries/LibJS/Tests/builtins/FinalizationRegistry/FinalizationRegistry.js

@@ -0,0 +1,33 @@
+test("constructor properties", () => {
+    expect(FinalizationRegistry).toHaveLength(1);
+    expect(FinalizationRegistry.name).toBe("FinalizationRegistry");
+});
+
+describe("errors", () => {
+    test("invalid callbacks", () => {
+        [-100, Infinity, NaN, 152n, undefined].forEach(value => {
+            expect(() => {
+                new FinalizationRegistry(value);
+            }).toThrowWithMessage(TypeError, "is not a function");
+        });
+    });
+    test("called without new", () => {
+        expect(() => {
+            FinalizationRegistry();
+        }).toThrowWithMessage(
+            TypeError,
+            "FinalizationRegistry constructor must be called with 'new'"
+        );
+    });
+});
+
+describe("normal behavior", () => {
+    test("typeof", () => {
+        expect(typeof new FinalizationRegistry(() => {})).toBe("object");
+    });
+
+    test("constructor with single callback argument", () => {
+        var a = new FinalizationRegistry(() => {});
+        expect(a instanceof FinalizationRegistry).toBeTrue();
+    });
+});