Fix passing arguments to VM dylib on Apple M1

The engine function pointer to vmMain used variadic arguments but
the vmMain function in the dylib has explicit arguments. Evidently
the arguments are stored on the stack and/or registers differently.

Found by fretn.

code/qcommon/qcommon.h

@@ -355,6 +355,8 @@ typedef enum {
 	TRAP_TESTPRINTFLOAT
 } sharedTraps_t;
 
+typedef intptr_t (QDECL *vmMainProc)(int callNum, int arg0, int arg1, int arg2, int arg3, int arg4, int arg5, int arg6, int arg7, int arg8, int arg9, int arg10, int arg11);
+
 void	VM_Init( void );
 vm_t	*VM_Create( const char *module, intptr_t (*systemCalls)(intptr_t *), 
 				   vmInterpret_t interpret );
@@ -1080,7 +1082,7 @@ NON-PORTABLE SYSTEM SERVICES
 void	Sys_Init (void);
 
 // general development dll loading for virtual machine testing
-void	* QDECL Sys_LoadGameDll( const char *name, intptr_t (QDECL **entryPoint)(int, ...),
+void	* QDECL Sys_LoadGameDll( const char *name, vmMainProc *entryPoint,
 				  intptr_t (QDECL *systemcalls)(intptr_t, ...) );
 void	Sys_UnloadDll( void *dllHandle );
 

code/qcommon/vm_local.h

@@ -154,7 +154,7 @@ struct vm_s {
 
 	// for dynamic linked modules
 	void		*dllHandle;
-	intptr_t			(QDECL *entryPoint)( int callNum, ... );
+	vmMainProc	entryPoint;
 	void (*destroy)(vm_t* self);
 
 	// for interpreted modules

code/sys/sys_main.c

@@ -579,7 +579,7 @@ Used to load a development dll instead of a virtual machine
 =================
 */
 void *Sys_LoadGameDll(const char *name,
-	intptr_t (QDECL **entryPoint)(int, ...),
+	vmMainProc *entryPoint,
 	intptr_t (*systemcalls)(intptr_t, ...))
 {
 	void *libHandle;