patch 8.2.1723: Vim9: Variable argument name cannot start with underscore Commit: https://github.com/vim/vim/commit/280227270c1c54794a6d88a305fac56d4b0c92a5 Author: Bram Moolenaar <Bram@vim.org> Date: Mon Sep 21 22:02:49 2020 +0200 patch 8.2.1723: Vim9: Variable argument name cannot start with underscore Problem: Vim9: Variable argument name cannot start with underscore. Solution: Use eval_isnamec1(). (closes https://github.com/vim/vim/issues/6988)