lib: expose primordials object

Expose the internal `primordials` object to help with Node.js core
development.

```console
$ node --expose-internals -r internal/test/binding lib/fs.js
(node:5299) internal/test/binding: These APIs are for internal testing
only. Do not use them.
(Use `node --trace-warnings ...` to show where the warning was created)
```

PR-URL: #36872
Reviewed-By: Bradley Farias <bradley.meck@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/internal/modules/cjs/loader.js

@@ -233,9 +233,9 @@ ObjectDefineProperty(Module, 'wrapper', {
   }
 });
 
-ObjectDefineProperty(Module.prototype, 'isPreloading', {
-  get() { return isPreloading; }
-});
+const isPreloadingDesc = { get() { return isPreloading; } };
+ObjectDefineProperty(Module.prototype, 'isPreloading', isPreloadingDesc);
+ObjectDefineProperty(NativeModule.prototype, 'isPreloading', isPreloadingDesc);
 
 let debug = require('internal/util/debuglog').debuglog('module', (fn) => {
   debug = fn;

lib/internal/test/binding.js

@@ -4,4 +4,9 @@ process.emitWarning(
   'These APIs are for internal testing only. Do not use them.',
   'internal/test/binding');
 
-module.exports = { internalBinding };
+if (module.isPreloading) {
+  globalThis.internalBinding = internalBinding;
+  globalThis.primordials = primordials;
+}
+
+module.exports = { internalBinding, primordials };