Fix MSVC compiler and linker errors

- Fix struct/class forward declaration mismatches (JAIAudience, JASTrack) causing different MSVC mangled names and unresolved symbols
- Add jsystem_stubs.cpp with stubs for JASHeap, JASVoiceBank, J3DShapeTable, JAUSection, JHICommBuf, HIO/HIO2, JOR

include/JSystem/J3DGraphBase/J3DDrawBuffer.h

@@ -26,6 +26,8 @@ inline f32 J3DCalcZValue(__REGISTER MtxP m, __REGISTER Vec v) {
     // clang-format on
 
     return out;
+#else
+    return m[2][0] * v.x + m[2][1] * v.y + m[2][2] * v.z + m[2][3];
 #endif
 }