Added original SDK code for Alien Swarm.

game/shared/weapon_parse_default.cpp

@@ -0,0 +1,20 @@
+//========= Copyright © 1996-2005, Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+//=============================================================================//
+
+#include "cbase.h"
+#include "weapon_parse.h"
+
+// memdbgon must be the last include file in a .cpp file!!!
+#include "tier0/memdbgon.h"
+
+// Default implementation for games that don't add custom data to the weapon scripts.
+FileWeaponInfo_t* CreateWeaponInfo()
+{
+	return new FileWeaponInfo_t;
+}
+
+
+