Remove "action" from Actor functions that don't actually need it

- An actor function really only needs to be an action function if:
  1. It can be called with no parameters specified, either because it takes
     none or because all its parameters are optional. This lets SetState()
     call it directly without creating a wrapper function for it.
  2. It wants access to the callingstate or stateowner parameters. Most
     functions don't care about them, so passing them is superfluous.

src/g_hexen/a_fighterquietus.cpp

@@ -26,7 +26,7 @@ static FRandom pr_fswordflame ("FSwordFlame");
 
 DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_DropWeaponPieces)
 {
-	PARAM_ACTION_PROLOGUE;
+	PARAM_SELF_PROLOGUE(AActor);
 	PARAM_CLASS(p1, AActor);
 	PARAM_CLASS(p2, AActor);
 	PARAM_CLASS(p3, AActor);

src/g_strife/a_thingstoblowup.cpp

@@ -28,7 +28,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_Bang4Cloud)
 
 DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_GiveQuestItem)
 {
-	PARAM_ACTION_PROLOGUE;
+	PARAM_SELF_PROLOGUE(AActor);
 	PARAM_INT(questitem);
 
 	// Give one of these quest items to every player in the game

src/info.h

@@ -345,4 +345,8 @@ void AddStateLight(FState *state, const char *lname);
 // Number of action paramaters
 #define NAP 3
 
+#define PARAM_SELF_PROLOGUE(type) \
+	PARAM_PROLOGUE; \
+	PARAM_OBJECT(self, type);
+
 #endif	// __INFO_H__

src/p_enemy.cpp

@@ -2773,7 +2773,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_VileChase)
 
 DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_ExtChase)
 {
-	PARAM_ACTION_PROLOGUE;
+	PARAM_SELF_PROLOGUE(AActor);
 	PARAM_BOOL		(domelee);
 	PARAM_BOOL		(domissile);
 	PARAM_BOOL_OPT	(playactive)	{ playactive = true; }

src/thingdef/thingdef_exp.h

@@ -881,6 +881,7 @@ public:
 	ExpEmit Emit(VMFunctionBuilder *build, bool tailcall);
 	bool CheckEmitCast(VMFunctionBuilder *build, bool returnit, ExpEmit &reg);
 	unsigned GetArgCount() const { return ArgList == NULL ? 0 : ArgList->Size(); }
+	PFunction *GetFunction() const { return Function; }
 	VMFunction *GetVMFunction() const { return Function->Variants[0].Implementation; }
 	bool IsDirectFunction();
 };

src/thingdef/thingdef_expression.cpp

@@ -3844,7 +3844,7 @@ VMFunction *FxReturnStatement::GetDirectFunction()
 	// then it can be a "direct" function. That is, the DECORATE
 	// definition can call that function directly without wrapping
 	// it inside VM code.
-	if (Call != NULL && Call->GetArgCount() == 0)
+	if (Call != NULL && Call->GetArgCount() == 0 && (Call->GetFunction()->Flags & VARF_Action))
 	{
 		return Call->GetVMFunction();
 	}