feat: 注入 harness 并补齐关键全局内建

crates/oxide_vm/tests/builtins_object_tests.rs

@@ -37,6 +37,18 @@ fn object_assign_copies() {
     assert!(result.is_object());
 }
 
+#[test]
+fn object_is_uses_same_value_semantics() {
+    let (_vm, result) = eval("Object.is(NaN, NaN)").unwrap();
+    assert_eq!(result, JsValue::bool(true));
+
+    let (_vm, result) = eval("Object.is(1, 1)").unwrap();
+    assert_eq!(result, JsValue::bool(true));
+
+    let (_vm, result) = eval("Object.is(1, '1')").unwrap();
+    assert_eq!(result, JsValue::bool(false));
+}
+
 #[test]
 fn object_get_own_property_descriptor_value() {
     let (_vm, result) = eval("Object.getOwnPropertyDescriptor({a:1},'a')").unwrap();