Specifically, functions that are run in the context of the test runner
are put in module `test/testutil.lua` while the functions that are run
in the context of the test session are put in
`test/functional/testnvim.lua`.
Closes https://github.com/neovim/neovim/issues/27004.
Problem:
'endofline' can be used to detect if a file ends of <EOL>, however
editorconfig can break this.
Solution:
Set 'endofline' during BufWritePre
Fixes: #24869
Rather than only check `editorconfig_enable` when the plugin is loaded,
check it each time the autocommand fires, so that users may enable or
disable it dynamically.
Also check for a buffer local version of the variable, so that
editorconfig can be enabled or disabled per-buffer.
