patch 8.1.0991: cannot build with a mix of features commit https://github.com/vim/vim/commit/975880b6e6de473b512995ef87ce072aaca934cf Author: Bram Moolenaar <Bram@vim.org> Date: Sun Mar 3 14:42:11 2019 +0100 patch 8.1.0991: cannot build with a mix of features Problem: Cannot build with FEAT_EVAL defined and FEAT_SEARCH_EXTRA undefined, and with FEAT_DIFF defined and FEAT_EVAL undefined. Solution: Add a couple of #ifdefs. (closes #4067)