patch 8.1.1565: MS-Windows: no sound support

Problem:    MS-Windows: no sound support.
Solution:   Add sound support for MS-Windows. (Yasuhiro Matsumoto, Ken Takata,
            closes #4522)
diff --git a/src/testdir/test_sound.vim b/src/testdir/test_sound.vim
index 1e2c455..e74aa13 100644
--- a/src/testdir/test_sound.vim
+++ b/src/testdir/test_sound.vim
@@ -10,6 +10,10 @@
 endfunc
 
 func Test_play_event()
+  if has('win32')
+    throw 'Skipped: Playing event with callback is not supported on Windows'
+  endif
+
   let id = sound_playevent('bell', 'PlayCallback')
   if id == 0
     throw 'Skipped: bell event not available'