patch 9.0.1801: Vim9 instanceof() fails in a def func

Problem:  Vim9 instanceof() fails in a def func
Solution: allow Objects in compile time check

closes: #12907

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>
diff --git a/src/testdir/test_vim9_class.vim b/src/testdir/test_vim9_class.vim
index 2c6a501..5f5528a 100644
--- a/src/testdir/test_vim9_class.vim
+++ b/src/testdir/test_vim9_class.vim
@@ -2436,6 +2436,20 @@
     assert_true(instanceof(b3, Mix1))
     assert_false(instanceof(b3, []))
     assert_true(instanceof(b3, [Base1, Base2, Intf1]))
+
+    def Foo()
+      var a1 = Base1.new()
+      var a2 = Base2.new()
+      var a3 = Base3.new()
+
+      assert_true(instanceof(a1, Base1))
+      assert_true(instanceof(a2, Base1))
+      assert_false(instanceof(a1, Base2))
+      assert_true(instanceof(a3, Mix1))
+      assert_false(instanceof(a3, []))
+      assert_true(instanceof(a3, [Base1, Base2, Intf1]))
+    enddef
+    Foo()
   END
   v9.CheckScriptSuccess(lines)
 enddef