patch 8.2.2444: Vim9: compile error with combination of operator and list

Problem:    Vim9: compile error with combination of operator and list.
Solution:   Generate constants before parsing a list or dict. (closes #7757)
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index 2239e76..aead431 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -1083,6 +1083,9 @@
         assert_equal('a0.123', 'a' .. 0.123)
       endif
 
+      assert_equal(3, 1 + [2, 3, 4][0])
+      assert_equal(5, 2 + {key: 3}['key'])
+
       set digraph
       assert_equal('val: true', 'val: ' .. &digraph)
       set nodigraph