patch 8.2.1812: Vim9: nested closure throws an internal error

Problem:    Vim9: nested closure throws an internal error.
Solution:   Do not skip a local variable with a partial. (closes #7065)
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index f335245..c3687cf 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -1388,6 +1388,20 @@
   CheckScriptSuccess(lines)
 enddef
 
+def Test_nested_closure_used()
+  var lines =<< trim END
+      vim9script
+      def Func()
+        var x = 'hello'
+        var Closure = {-> x}
+        g:Myclosure = {-> Closure()}
+      enddef
+      Func()
+      assert_equal('hello', g:Myclosure())
+  END
+  CheckScriptSuccess(lines)
+enddef
+
 def Test_nested_closure_fails()
   var lines =<< trim END
     vim9script