\Drupal::classResolver() now takes an optional argument to directly load a class

The \Drupal class is all about syntactic sugar in bridging our procedural code to our object-orientated code. Only the getInstanceFromDefinition method is likely to be called on \Drupal::classResolver(), so in order to make it more helpful it now allows

\Drupal::classResolver(stdClass::class)

as a shortcut for

\Drupal::classResolver()->getInstanceFromDefinition(stdClass::class)

Calling \Drupal::classResolver() without an argument will still return the class resolver like before.

Before

\Drupal::classResolver()->getInstanceFromDefinition(FieldLayoutBuilder::class)->buildForm($form, $display);

After

\Drupal::classResolver(FieldLayoutBuilder::class)->buildForm($form, $display);