[PATCH v6 0/2] MR8466: ntdll: Also restore rbp before calling user mode callback.

[Yuxuan Shui (＠yshui)]

If wine dlls are built with frame pointers enabled, the frame pointer will be
used during unwinding.

If we don't restore frame pointer before calling the user mode callback, then
later when the unwinder encounters the user mode callback frame, it will set
the frame pointer to something unexpected (depends on what it was during
`call_user_mode_callback`). Then for the subsequent frame it adjusts the stack
pointer based on the frame pointer, thus derailing the unwinding process.

--
  v6: ntdll: Also restore rbp before calling user mode callback.
      user32/tests: Test unwinding through a user callback.

https://gitlab.winehq.org/wine/wine/-/merge_requests/8466