This was accidentally setting `CurrentSize` instead of just returning
the newly allocated size to the frontend. This was causing the frontend
to then fail to detect the reallocation actually occured and no longer
get stats for new threads.
Also happened to not use `NewSize` but instead `CurrentSize * 2` which
didn't matter as it matched the growth pattern, but was technically
incorrect.
Fixes SHM stats since the introduction of the unixlib, ezpz.
Centralizes all the nasty behaviour that will end up breaking when WINE
eventually turns on userspace syscall dispatch. Pushes all of the logic
in to the UnixLib. Support both paths until everyone is migrated to
supporting the UnixLib, then we can delete the bit of code duplication
between the PE side and UnixLib side.
Helpful that everything that gets punched through the UnixLib is
optional, so worst case some optional bits can break for a while.
Ryan Houdek