Make autoload exception more specific (#777)

This is a nice-to-have ([as I'm currently overriding it](https://github.com/psalm/laravel-psalm-plugin/commit/a700c89061d151d1c08851abd93d834f9183534d)), but might help other packages.

src/Console/MetaCommand.php

@@ -135,7 +135,7 @@ class MetaCommand extends Command
     protected function registerClassAutoloadExceptions()
     {
         spl_autoload_register(function ($class) {
-            throw new \Exception("Class '$class' not found.");
+            throw new \ReflectionException("Class '$class' not found.");
         });
     }