[Bug 15949] MSYS does not integrate with MinGW install correctly

https://bugs.winehq.org/show_bug.cgi?id=15949

--- Comment #8 from Jeff Zaroyko  ---
Same for wine-3.13.  The post-install script gets stuck while the installer GUI
is at 100%.

Per the original report /mingw is empty and `mount 'c:MinGW' /mingw` returns
"mount: /mingw: Function not implemented".   That mount is already set in
/etc/fstab.

Running the following from `wineconsole cmd` manually still doesn't produce a
working environment
C:\windows\system32\cmd.exe /s/c c:\msys\1.0\postinstall\pi.bat pi.sh