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

src/f_pc/f_pc_profile.cpp

@@ -5,7 +5,16 @@
 
 #include "f_pc/f_pc_profile.h"
 
+
+#ifndef __MWERKS__
+// Forward declare the static list from f_pc_profile_lst.cpp
+extern process_profile_definition* g_fpcPfLst_ProfileList[];
+// On PC: Direct pointer to static array
+process_profile_definition** g_fpcPf_ProfileList_p = g_fpcPfLst_ProfileList;
+#else
+// On Console: Pointer initialized by REL module prolog
 process_profile_definition** g_fpcPf_ProfileList_p;
+#endif
 
 process_profile_definition* fpcPf_Get(s16 i_profname) {
     int index = i_profname;