First part of Proton shared memory series. The full branch can be seen at https://gitlab.winehq.org/rbernon/wine/-/commits/mr/shared-memories.
-- v18: user32: Use the desktop shared data for GetCursorPos(). include: Add ReadNoFence64 inline helpers. server: Expose the desktop shared mapping to clients. server: Add a sequence number to the shared data. server: Move the cursor position and last change time to the shared data. server: Create a desktop shared mapping.