Update to Wine 5.6. This includes the following changes:

• Still more Media Foundation work.
• Improvements to Active Directory LDAP support.
• A few more modules converted to PE.
• Improvements to gdb proxy mode.
• Various bug fixes.

My fix for a build problem on some versions of FreeBSD in
files/patch-dlls-dbghelp has been accepted upstream, so remove here.

The Wine Staging patch set is lagging once again; we'll add support
once it's available.