test: fix common.mustCall length and name properties

Reassign `name` and `length` properties to the returned function to not
break code that relies on it.

PR-URL: https://github.com/nodejs/node/pull/38464
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

test/common/index.js

@@ -387,10 +387,28 @@ function _mustCallInner(fn, criteria = 1, field) {
 
   mustCallChecks.push(context);
 
-  return function() {
+  const _return = function() { // eslint-disable-line func-style
     context.actual++;
     return fn.apply(this, arguments);
   };
+  // Function instances have own properties that may be relevant.
+  // Let's replicate those properties to the returned function.
+  // Refs: https://tc39.es/ecma262/#sec-function-instances
+  Object.defineProperties(_return, {
+    name: {
+      value: fn.name,
+      writable: false,
+      enumerable: false,
+      configurable: true,
+    },
+    length: {
+      value: fn.length,
+      writable: false,
+      enumerable: false,
+      configurable: true,
+    },
+  });
+  return _return;
 }
 
 function hasMultiLocalhost() {