Indicate Decode As support in the -G dissector-tables output.

Change-Id: I95535ba11fdcac37057d1441e850ddf5455d32cf
Reviewed-on: https://code.wireshark.org/review/24141
Reviewed-by: Guy Harris <guy@alum.mit.edu>

epan/packet.c

@@ -3319,6 +3319,8 @@ dissector_dump_dissector_tables_display (gpointer key, gpointer user_data _U_)
 	default:
 		break;
 	}
+	ws_debug_printf("\tDecode As %ssupported",
+	    table->supports_decode_as ? "" : "not ");
 	ws_debug_printf("\n");
 }