ksys/phys: Finish SystemData and start implementing GroupFilter

src/KingSystem/Physics/System/physMemSystem.h

@@ -6,6 +6,7 @@
 namespace ksys::phys {
 
 class RigidBody;
+class SystemGroupHandler;
 
 class MemSystem {
     SEAD_SINGLETON_DISPOSER(MemSystem)
@@ -14,6 +15,8 @@ public:
         void sub_7100FA6C8C(bool, RigidBody*);
     };
 
+    void removeSystemGroupHandler(SystemGroupHandler* handler);
+
     u8 _20[0x140];
     Struct160* _160;
 };