When a service is decorated with a private decorator, and there is a deprecated alias pointing to the original service, the compiler passes could invert the alias chain. This caused the original service ID to become an alias pointing to the deprecated interface, triggering false deprecation warnings.

Two issues fixed:

1. ResolveReferencesToAliasesPass was not preserving the deprecation flag when resolving alias chains
2. ReplaceAliasByActualDefinitionPass used non-deterministic iteration order, allowing deprecated aliases to "win" when renaming definitions

Example scenario:

services:
  my_service:
    class: App\MyService

  App\MyServiceInterface:
    alias: my_service
    deprecated:
      package: 'my/package'
      version: '1.0'

  App\MyServiceDecorator:
    decorates: my_service
    public: false

Before fix: $container->get('my_service') would trigger deprecation warning
After fix: Only $container->get('App\MyServiceInterface') triggers deprecation warning