[HttpKernel][DI] Enable Kernel to implement CompilerPassInterface

Author: nicolas-grekas

CHANGELOG.md

@@ -4,6 +4,7 @@ CHANGELOG
 3.4.0
 -----
 
+ * moved the `ExtensionCompilerPass` to before-optimization passes with priority -1000
  * deprecated "public-by-default" definitions and aliases, the new default will be "private" in 4.0
  * added `EnvVarProcessorInterface` and corresponding "container.env_var_processor" tag for processing env vars
  * added support for ignore-on-uninitialized references

Compiler/PassConfig.php

@@ -45,10 +45,10 @@ public function __construct()
                 new ResolveInstanceofConditionalsPass(),
                 new RegisterEnvVarProcessorsPass(),
             ),
+            -1000 => array(new ExtensionCompilerPass()),
         );
 
         $this->optimizationPasses = array(array(
-            new ExtensionCompilerPass(),
             new ResolveChildDefinitionsPass(),
             new ServiceLocatorTagPass(),
             new DecoratorServicePass(),