patch 8.1.0851: feedkeys() with "L" does not work properly

Problem:    feedkeys() with "L" does not work properly.
Solution:   Do not set typebuf_was_filled when using "L". (Ozaki Kiichi,
            closes #3885)
diff --git a/src/testdir/test_timers.vim b/src/testdir/test_timers.vim
index 78ec005..e900b1f 100644
--- a/src/testdir/test_timers.vim
+++ b/src/testdir/test_timers.vim
@@ -251,15 +251,14 @@
 endfunc
 
 func Test_getchar_zero()
-  if has('win32')
+  if has('win32') && !has('gui_running')
     " Console: no low-level input
-    " GUI: somehow doesn't work
     return
   endif
 
   " Measure the elapsed time to avoid a hang when it fails.
   let start = reltime()
-  let id = timer_start(20, {id -> feedkeys('x', 'L')})
+  let id = timer_start(20, {-> feedkeys('x', 'L')})
   let c = 0
   while c == 0 && reltimefloat(reltime(start)) < 0.2
     let c = getchar(0)