Introduce vim.secure.trust() to programmatically manage the trust
database. Use this function in a new :trust ex command which can
be used as a simple frontend.

Resolves: https://github.com/neovim/neovim/issues/21092
Co-authored-by: Gregory Anders <greg@gpanders.com>
Co-authored-by: ii14 <ii14@users.noreply.github.com>

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")`.

Change the file modification time instead of uptime.

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:    Illegal memory access if popup menu items are changed while the
            menu is visible. (Tomáš Janoušek)
Solution:   Make a copy of the text. (closes vim/vim#7537)

https://github.com/vim/vim/commit/38455a921395a56690790c8c1d28c1c43ca04c8a

Co-authored-by: Bram Moolenaar <Bram@vim.org>

- `:write ++p foo/bar/baz.txt` should create parent directories `foo/bar/` if
   they do not exist
    - Note: `:foo ++…` is usually for options. No existing options have
      a single-char abbreviation (presumably by design), so it's safe to
      special-case `++p` here.
- Same for `writefile(…, 'foo/bar/baz.txt', 'p')`
- `BufWriteCmd` can see the ++p flag via `v:cmdarg`.

closes #19884

The environment variable CIRRUS_CI is manually passed to RunTests.cmake
as it doesn't get passed when using cmake script mode.