Fix ninja all_source compilation errors

include/d/d_bg_s_gnd_chk.h

@@ -69,7 +69,7 @@ class dBgS_CamGndChk : public dBgS_GndChk {
 public:
     dBgS_CamGndChk() { /* SetCam(); */ }
 
-    virtual ~dBgS_CamGndChk();
+    virtual ~dBgS_CamGndChk() {}
 };
 
 class dBgS_CamGndChk_Wtr : public dBgS_CamGndChk {

include/d/d_cam_param.h

@@ -125,8 +125,8 @@ public:
     dCamParam_c(s32);
     virtual ~dCamParam_c();
 
-    void Flag(s32, u16);
-    void Val(s32, int);
+    void Flag(s32, u16) {}
+    void Val(s32, int) {}
     void Change(s32);
     void SearchStyle(u32);
     void ratiof(f32, f32, f32, f32);

include/d/d_camera.h

@@ -34,7 +34,7 @@ struct dCamera__EventParam {
 
 class d2DBSplinePath {
 public:
-    ~d2DBSplinePath();
+    ~d2DBSplinePath() {}
     /* 0x00 */ int mKeyframeCur;
     /* 0x04 */ int mTimer;
     /* 0x08 */ int mKeyframeNum;
@@ -64,8 +64,8 @@ public:
 class dCamera_c {
 public:
     struct BG {
-        BG();
-        ~BG();
+        BG() {}
+        ~BG() {}
         u8 temp[0xB0];
     };
 
@@ -356,9 +356,9 @@ public:
     void SetExtendedPosition(cXyz*);
     void ScopeViewMsgModeOff();
 
-    void Bank();
-    void Up();
-    void Center();
+    void Bank() {}
+    void Up() {}
+    void Center() {}
 
     void StartEventCamera(int, int, ...);
     void EndEventCamera(int);