also:
- add listing of error codes to avoid collisions
- cpu: add cpu_MemoryBarrier
- wchar: warn whenever a character is replaced/invalid bytes are
encountered
This was SVN commit r7189.
- displaying symbol values requires stack pointer, not frame pointer
- update debug_IsPointerBogus
- skip-n-frames code changed to skip-all-frames-up-to-func (more
reliable in the face of inlining)
debug.cpp: cleanup
This was SVN commit r6410.