- route menu's CheckGame call through SysCallbacks.

Needed to be able to move the menu into the backend.

src/common/engine/i_interface.h

@@ -22,6 +22,7 @@ struct SystemCallbacks
 	void (*MenuDim)();
 	FString(*GetPlayerName)(int i);
 	bool (*DispatchEvent)(event_t* ev);
+	bool (*CheckGame)(const char* nm);
 };
 
 extern SystemCallbacks sysCallbacks;

src/d_main.cpp

@@ -2741,6 +2741,11 @@ static bool System_DispatchEvent(event_t* ev)
 	return false;
 }
 
+static bool System_CheckGame(const char* name)
+{
+	return CheckGame(name, false);
+}
+
 bool System_NetGame()
 {
 	return netgame;
@@ -3073,6 +3078,7 @@ static int D_DoomMain_Internal (void)
 		System_M_Dim,
 		System_GetPlayerName,
 		System_DispatchEvent,
+		System_CheckGame,
 	};