[saco] Implement/match CVehicle::IsSirenOn()

saco/game/vehicle.cpp

@@ -204,5 +204,12 @@ void CVehicle::SetSirenOn(BYTE byteState)
 
 //-----------------------------------------------------------
 
+BOOL CVehicle::IsSirenOn()
+{
+	return (m_pVehicle->bSirenOn == 1);
+}
+
+//-----------------------------------------------------------
+
 //-----------------------------------------------------------
 

saco/game/vehicle.h

@@ -45,6 +45,7 @@ public:
 	BOOL  HasADriver();
 
 	void    SetSirenOn(BYTE byteState);
+	BOOL    IsSirenOn();
 
 	void    SetEngineState(BOOL bState);