tests: stub out virfilewrapper.c on Win32
tests: stub out virfilewrapper.c on Win32

The Win32 platform can not do link time overrides in the same way
that we can on POSIX / ELF based platforms, so we cannot build
the virfilewrapper.c code reliably. Just stub it out on Win32
so it is a no-op. Tests that use this file are already written
to skip on Win32.

Signed-off-by: Daniel P. Berrange <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

fabianfreyer/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,andreabolognani/libvirt,libvirt/libvirt,eskultety/libvirt,eskultety/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,olafhering/libvirt,crobinso/libvirt,datto/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,libvirt/libvirt,nertpinx/libvirt,datto/libvirt,VenkatDatta/libvirt,datto/libvirt,zippy2/libvirt,libvirt/libvirt,olafhering/libvirt,zippy2/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,crobinso/libvirt,nertpinx/libvirt,jardasgit/libvirt,jfehlig/libvirt,olafhering/libvirt,datto/libvirt,libvirt/libvirt,andreabolognani/libvirt,olafhering/libvirt,andreabolognani/libvirt,jfehlig/libvirt,nertpinx/libvirt,jfehlig/libvirt,datto/libvirt,zippy2/libvirt,jardasgit/libvirt,eskultety/libvirt,andreabolognani/libvirt,jardasgit/libvirt,eskultety/libvirt,crobinso/libvirt,eskultety/libvirt,crobinso/libvirt,jardasgit/libvirt,zippy2/libvirt,nertpinx/libvirt,VenkatDatta/libvirt