src: remove usage of deprecated debug API

Debug::GetMirror is used in contextify to force loading of the debug
context. There is a better way to achieve this.

PR-URL: nodejs/node#11437
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

src/node_contextify.cc

@@ -252,7 +252,8 @@ class ContextifyContext {
     Environment* env = Environment::GetCurrent(args);
     if (debug_context.IsEmpty()) {
       // Force-load the debug context.
-      Debug::GetMirror(args.GetIsolate()->GetCurrentContext(), args[0]);
+      auto dummy_event_listener = [] (const Debug::EventDetails&) {};
+      Debug::SetDebugEventListener(args.GetIsolate(), dummy_event_listener);
       debug_context = Debug::GetDebugContext(args.GetIsolate());
       CHECK(!debug_context.IsEmpty());
       // Ensure that the debug context has an Environment assigned in case