all: Fix compiler errors

include/nn/g3d/ResSceneAnim.h

@@ -11,7 +11,7 @@ namespace nn {
 namespace g3d {
 class ResLightAnim;
 class ResFogAnim;
-struct BindFuncTable;
+class BindFuncTable;
 
 class ResSceneAnim {
 public:

include/nn/g3d/ViewVolume.h

@@ -3,7 +3,7 @@
 #include "nn/types.h"
 
 namespace nn::util::neon {
-class MatrixRowMajor4x3fType;
+struct MatrixRowMajor4x3fType;
 }
 
 namespace nn::g3d {

include/nn/nfp/nfp.h

@@ -3,7 +3,7 @@
 #include <nn/types.h>
 
 namespace nn::os {
-class SystemEventType;
+struct SystemEventType;
 }  // namespace nn::os
 
 namespace nn::nfp {

include/nn/ui2d/Types.h

@@ -1,3 +1,4 @@
+#pragma once
 
 namespace nn::ui2d {
 

include/nn/ui2d/Util.h

@@ -1,12 +1,9 @@
 #pragma once
 
 #include <nn/gfx/gfx_Device.h>
+#include <nn/gfx/gfx_Types.h>
 #include <nn/util/MathTypes.h>
 
-namespace nn::gfx {
-class MemoryPool;
-}  // namespace nn::gfx
-
 namespace nn::ui2d {
 
 class AnimTransform;

include/nn/vfx/Resource.h

@@ -9,10 +9,10 @@
 namespace nn {
 namespace vfx {
 
-struct Heap;
+class Heap;
 struct EmitterResource;
 struct EmitterSetResource;
-struct System;
+class System;
 
 namespace detail {
 struct BinaryData;

include/nn/vfx/System.h

@@ -12,7 +12,7 @@
 namespace nn {
 namespace vfx {
 
-struct Heap;
+class Heap;
 
 class System {
 public: