patch 8.2.2558: no error if a lambda argument shadows a variable

Problem:    No error if a lambda argument shadows a variable.
Solution:   Check that the argument name shadows a local, argument or script
            variable. (closes #7898)
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index cda1ffd..26a6932 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -2843,7 +2843,7 @@
 
   # lambda method call
   l = [2, 5]
-  l->((l) => add(l, 8))()
+  l->((ll) => add(ll, 8))()
   assert_equal([2, 5, 8], l)
 
   # dict member
@@ -3034,8 +3034,8 @@
 enddef
 
 func Test_expr7_trailing_fails()
-  call CheckDefFailure(['var l = [2]', 'l->((l) => add(l, 8))'], 'E107:', 2)
-  call CheckDefFailure(['var l = [2]', 'l->((l) => add(l, 8)) ()'], 'E274:', 2)
+  call CheckDefFailure(['var l = [2]', 'l->((ll) => add(ll, 8))'], 'E107:', 2)
+  call CheckDefFailure(['var l = [2]', 'l->((ll) => add(ll, 8)) ()'], 'E274:', 2)
 endfunc
 
 func Test_expr_fails()