debug: activate inspector with _debugProcess

This pull request switches the signal handler to start inspector socket
server instead of the legacy V8 debug protocol.

PR-URL: #11431

Fixes: #8464
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

Author: Eugene Ostroukhov

node.gypi

@@ -77,9 +77,11 @@
       ],
       'sources': [
         'src/inspector_agent.cc',
+        'src/inspector_io.cc',
         'src/inspector_socket.cc',
         'src/inspector_socket_server.cc',
         'src/inspector_agent.h',
+        'src/inspector_io.h',
         'src/inspector_socket.h',
         'src/inspector_socket_server.h',
       ],