To make DDLOCK_DISCARDCONTENTS actually do anything. The MAPPABLE flag
is now redundant.

They are not needed any more, resource_access_from_pool takes care of
this.

It segfaults on Win7 + Nvidia Kepler and apparently returns different
return values on Windows 8. Since this functionality isn't supported on
any HW I doubt games will care.

Depth wraps around at 65536 but list supports more elements.

The standard keyboard shortcut for switching the keyboard layout is Command-
Space, but the Mac driver never sees the Space key press.  So, Wine only sees
a press and release of Alt, which puts focus on the menu bar.  This prevents
that focus change.

Sim City 4 uses this flag. The main problem I noticed was with
WINED3D_MAP_DISCARD handling introduced for surfaces in patches that
aren't yet in the tree, but the difference already matters for older
cards because of video memory accounting.