patch 9.1.1285: Vim9: no error message for missing method after "super."

Problem:  Vim9: no error message for missing method after "super."
Solution: output an error message, add a few more tests
          (Yegappan Lakshmanan).

closes: #17070

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
index 41b54aa..be95c64 100644
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -1060,6 +1060,16 @@
   END
   call v9.CheckDefAndScriptSuccess(lines)
 
+  " Error in the second expression of "<<"
+  let lines =<< trim END
+    vim9script
+    def Fn()
+      var x = 1 << y
+    enddef
+    defcompile
+  END
+  call v9.CheckSourceFailure(lines, 'E1001: Variable not found: y')
+
   let lines =<< trim END
     # Use in a lambda function
     const DivBy2Ref_A = (n: number): number => n >> 1