fix(ext): use `String#toWellFormed` in ext/webidl and ext/node (#21054)

Fixes #18802 

This PR adds `util.toUSVString` to node:util:

```js
import util from "node:util";
util.toUSVString("string\ud801"); // => "string\ufffd"
```

2 files changed, 9 insertions, 2 deletions

diff --git a/cli/tests/node_compat/test/parallel/test-util.js b/cli/tests/node_compat/test/parallel/test-util.js
index 5d1ed9b30..eaffc7f6d 100644
--- a/cli/tests/node_compat/test/parallel/test-util.js
+++ b/cli/tests/node_compat/test/parallel/test-util.js
@@ -161,8 +161,7 @@ assert.strictEqual(util.isFunction(function() {}), true);
 assert.strictEqual(util.isFunction(), false);
 assert.strictEqual(util.isFunction('string'), false);
 
-// TODO(wafuwafu13): Enable this when `toUSVString` is ready.
-// assert.strictEqual(util.toUSVString('string\ud801'), 'string\ufffd');
+assert.strictEqual(util.toUSVString('string\ud801'), 'string\ufffd');
 
 {
   assert.strictEqual(util.types.isNativeError(new Error()), true);
diff --git a/cli/tests/unit_node/util_test.ts b/cli/tests/unit_node/util_test.ts
index 64020141a..e90eed831 100644
--- a/cli/tests/unit_node/util_test.ts
+++ b/cli/tests/unit_node/util_test.ts
@@ -209,6 +209,14 @@ Deno.test({
 });
 
 Deno.test({
+  name: "[util] toUSVString",
+  fn() {
+    assertEquals(util.toUSVString("foo"), "foo");
+    assertEquals(util.toUSVString("bar\ud801"), "bar\ufffd");
+  },
+});
+
+Deno.test({
   name: "[util] isDate",
   fn() {
     // Test verifies the method is exposed. See _util/_util_types_test for details