added deprecation info

Author: OskarStark

components/http_kernel.rst

@@ -615,6 +615,19 @@ kernel.terminate             ``KernelEvents::TERMINATE``             :class:`Sym
 kernel.exception             ``KernelEvents::EXCEPTION``             :class:`Symfony\\Component\\HttpKernel\\Event\\ExceptionEvent`
 ===========================  ======================================  ========================================================================
 
+.. deprecated:: 4.3
+
+    Since Symfony 4.3, most of the event classes were renamed.
+    The following old classes were deprecated:
+
+    * `GetResponseEvent` renamed to :class:`Symfony\\Component\\HttpKernel\\Event\\RequestEvent`
+    * `FilterControllerEvent` renamed to :class:`Symfony\\Component\\HttpKernel\\Event\\ControllerEvent`
+    * `FilterControllerArgumentsEvent` renamed to :class:`Symfony\\Component\\HttpKernel\\Event\\ControllerArgumentsEvent`
+    * `GetResponseForControllerResultEvent` renamed to :class:`Symfony\\Component\\HttpKernel\\Event\\ViewEvent`
+    * `FilterResponseEvent` renamed to :class:`Symfony\\Component\\HttpKernel\\Event\\ResponseEvent`
+    * `PostResponseEvent` renamed to :class:`Symfony\\Component\\HttpKernel\\Event\\TerminateEvent`
+    * `GetResponseForExceptionEvent` renamed to :class:`Symfony\\Component\\HttpKernel\\Event\\ExceptionEvent`
+
 .. _http-kernel-working-example:
 
 A full Working Example