Extend the capabilities of is_os to detect more platforms such as
freebsd and openbsd. Also remove `iswin()` helper function as it can be
replaced by `is_os("win")`.
This is essentially a convenience wrapper around the `pending()`
function, similar to `skip_fragile()` but more general-purpose.
Also remove `pending_win32` function as it can be replaced by
`skip(iswin())`.
Problem: Insufficient testing for reading/writing files.
Solution: Add more tests. (Yegappan Lakshmanan, closesvim/vim#6257)
Add "ui_delay" to test_override() and use it for the CTRL-O test.
b340baed9f
Omit test_override().
Reorder test_writefile.vim to match Vim.
Problem: When reloading not all properties are detected.
Solution: Add the "edit" value to v:fcs_choice. (Rob Pilling, closesvim/vim#9579)
8196e94a8b
Cherry-pick some test changes from patch 8.1.1826.
