fix(ext/node): improve comparison of faked objects in deepStrictEqual (#29819)

This commit improves the handling of objects with faked prototypes in
`deepStrictEqual`. This enables `parallel/test-assert-checktag.js`

- `Date` objects are checked by `core.isDate`
- In object comparison, now it checks `obj.toString()` output (The
difference of `Symbol.toStringTag` is now detected).
- Stoped using std's assertion error message for `deepStrictEqual`, but
started using Node.js version of diff string. Now the diff expression is
more compatible with Node.

ext/node/polyfills/_util/std_asserts.ts

@@ -1,9 +1,8 @@
 // Copyright 2018-2025 the Deno authors. MIT license.
 // vendored from std/assert/mod.ts
 
-import { primordials } from "ext:core/mod.js";
+import { core, primordials } from "ext:core/mod.js";
 const {
-  DatePrototype,
   ArrayPrototypeJoin,
   ArrayPrototypeMap,
   DatePrototypeGetTime,
@@ -13,6 +12,7 @@ const {
   ObjectIs,
   ObjectKeys,
   ObjectPrototypeIsPrototypeOf,
+  ObjectPrototypeToString,
   ReflectHas,
   ReflectOwnKeys,
   RegExpPrototype,
@@ -89,10 +89,10 @@ export function equal(c: unknown, d: unknown): boolean {
     ) {
       return String(a) === String(b);
     }
-    if (
-      ObjectPrototypeIsPrototypeOf(DatePrototype, a) &&
-      ObjectPrototypeIsPrototypeOf(DatePrototype, b)
-    ) {
+    if (core.isDate(a) || core.isDate(b)) {
+      if (!core.isDate(a) || !core.isDate(b)) {
+        return false;
+      }
       const aTime = DatePrototypeGetTime(a);
       const bTime = DatePrototypeGetTime(b);
       // Check for NaN equality manually since NaN is not
@@ -112,6 +112,9 @@ export function equal(c: unknown, d: unknown): boolean {
       if (a && b && !constructorsEqual(a, b)) {
         return false;
       }
+      if (ObjectPrototypeToString(a) !== ObjectPrototypeToString(b)) {
+        return false;
+      }
       if (
         ObjectPrototypeIsPrototypeOf(WeakMapPrototype, a) ||
         ObjectPrototypeIsPrototypeOf(WeakMapPrototype, b)