patch 9.0.1627: no generic mechanism to test syntax plugins Commit: https://github.com/vim/vim/commit/46acad7284cba7842b5e505fa3d07e99806d246f Author: Bram Moolenaar <Bram@vim.org> Date: Sun Jun 11 19:04:18 2023 +0100 patch 9.0.1627: no generic mechanism to test syntax plugins Problem: No generic mechanism to test syntax plugins. Solution: Add a syntax plugin test mechanism, using screendumps. Add a simple test for "c".