qga/vss-win32: check old VSS SDK headers

The VssCoordinator & VssAdmin interfaces have been moved to vsadmin.h in
the Windows SDK.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220222194008.610377-3-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/meson.build b/meson.build
index 80c48e4..ad43278 100644
--- a/meson.build
+++ b/meson.build
@@ -1954,12 +1954,15 @@
   }'''))
 
 have_vss = false
+have_vss_sdk = false # old xp/2003 SDK
 if targetos == 'windows' and link_language == 'cpp'
   have_vss = cxx.compiles('''
     #define __MIDL_user_allocate_free_DEFINED__
     #include <vss.h>
     int main(void) { return VSS_CTX_BACKUP; }''')
+  have_vss_sdk = cxx.has_header('vscoordint.h')
 endif
+config_host_data.set('HAVE_VSS_SDK', have_vss_sdk)
 
 have_ntddscsi = false
 if targetos == 'windows'