patch 8.1.2247: "make vimtags" does not work in runtime/doc Commit: https://github.com/vim/vim/commit/e890b9f5dd3ae76e301b2df7f3151366acaba5dc Author: Bram Moolenaar <Bram@vim.org> Date: Sun Nov 3 18:38:47 2019 +0100 patch 8.1.2247: "make vimtags" does not work in runtime/doc Problem: "make vimtags" does not work in runtime/doc. Solution: Test existence with "which" instead of "test -x". (Ken Takata)