LibJS: Removed a fixme in a test of BigInt.prototype.valueOf

Author: https://github.com/tuqqu
Commit: https://github.com/SerenityOS/serenity/commit/54388792774
Pull-request: https://github.com/SerenityOS/serenity/pull/6244
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibJS/Tests/builtins/BigInt/BigInt.prototype.valueOf.js

@@ -1,8 +1,7 @@
 test("basic functionality", () => {
     expect(BigInt.prototype.valueOf).toHaveLength(0);
     expect(typeof BigInt(123).valueOf()).toBe("bigint");
-    // FIXME: Uncomment once we support Object() with argument
-    // expect(typeof Object(123n).valueOf()).toBe("bigint");
+    expect(typeof Object(123n).valueOf()).toBe("bigint");
 });
 
 test("calling with non-BigInt |this|", () => {