[Bug 43893] Disable use of SHM extension through environment variable

https://bugs.winehq.org/show_bug.cgi?id=43893

--- Comment #4 from Panard  ---
Created attachment 59517
  --> https://bugs.winehq.org/attachment.cgi?id=59517
wine-WINE_X11_NO_MITSHM.patch

For the record, here is a patch for runtime disabling of XShm for Wine by
setting envvar WINE_X11_NO_MITSHM=1.
It allows to easily fix shm related issues in specific environments, without
having to restrict the server features or to provides alternative binaries.

There is unfortunately no other easy way to disable XShm on client side (that's
why Qt and Java both provides a similar mechanism).