[Bug 54550] New: Move registry functions implementations into offreg.dll

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54550

Bug ID: 54550
           Summary: Move registry functions implementations into
                    offreg.dll
           Product: Wine
           Version: unspecified
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P2
         Component: advapi32
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

https://learn.microsoft.com/en-us/windows/win32/devnotes/offline-registry-li...

This is a library to work with registry files. It is not shipped with Windows,
but is a part of WDK, so usually apps needing it bring one with itself. But
AFAIK Wine registry format is different from Windows one.

Also it'd be nice to be able to manipulate Wine registry from the apps native
to the host.

So it is proposed to

1. move all the impls of the registry format into a unix library
`libwineoffreg.so`
2. generate `offreg.dll.so` and `offreg.dll` using `libwineoffreg.so`
3. use it from `advapi32.dll`