patch 8.2.0771: Vim9: cannot call a compiled closure from not compiled code

Problem:    Vim9: cannot call a compiled closure from not compiled code.
Solution:   Pass funcexe to call_user_func().
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index c74b4a4..100d86a 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -792,5 +792,15 @@
   assert_equal('text!!!', Closure('!!!'))
 enddef
 
+func GetResult(Ref)
+  return a:Ref('some')
+endfunc
+
+def Test_call_closure_not_compiled()
+  let text = 'text'
+  g:Ref = {s ->  s .. text}
+  assert_equal('sometext', GetResult(g:Ref))
+enddef
+
 
 " vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker