src: remove unused internalBinding('config') properties

Remove the following properties:

- `preserveSymlinks`
- `preserveSymlinksMain`
- `experimentalModules`
- `userLoader`
- `experimentalVMModules`
- `experimentalREPLAwait`
- `exposeInternals`

We used to use them to pass cli option values from C++ into
JS, but now the values are obtained in JS land using
`require('internal/options').getOptionValue` instead so they
are unused.

Also removes `test/parallel/test-internal-modules-expose.js`
which tests `--expose-internals`.
We already have hundreds of tests depending on `--expose-internals`,
they are more than enough to test the functionality of the flag.

PR-URL: #25463
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Refael Ackermann <refack@gmail.com>

src/node_config.cc

@@ -73,28 +73,6 @@ static void Initialize(Local<Object> target,
 
 #endif  // NODE_HAVE_I18N_SUPPORT
 
-  if (env->options()->preserve_symlinks)
-    READONLY_TRUE_PROPERTY(target, "preserveSymlinks");
-  if (env->options()->preserve_symlinks_main)
-    READONLY_TRUE_PROPERTY(target, "preserveSymlinksMain");
-
-  if (env->options()->experimental_modules) {
-    READONLY_TRUE_PROPERTY(target, "experimentalModules");
-    const std::string& userland_loader = env->options()->userland_loader;
-    if (!userland_loader.empty()) {
-      READONLY_STRING_PROPERTY(target, "userLoader",  userland_loader);
-    }
-  }
-
-  if (env->options()->experimental_vm_modules)
-    READONLY_TRUE_PROPERTY(target, "experimentalVMModules");
-
-  if (env->options()->experimental_repl_await)
-    READONLY_TRUE_PROPERTY(target, "experimentalREPLAwait");
-
-  if (env->options()->expose_internals)
-    READONLY_TRUE_PROPERTY(target, "exposeInternals");
-
   READONLY_PROPERTY(target,
                     "bits",
                     Number::New(env->isolate(), 8 * sizeof(intptr_t)));