The test is also split in several blocks and heavily modernized. This was
done to prevent the following quoting and escaping problems during migration:
- the vim command `put =...` treats double quotes as the start of a comment so
they have to be escaped with a backslash
- when inserting control characters on the command line they have to be
escaped with <C-V>
The parts one and two of the test are functional identical so they are wrapped
in a local function. The only difference was which letters where used to test
the same feature.
Part six did test a flag in 'cpoptions' that has been removed in neovim. It
has therefore been removed as well.
Reviewed-by: Michael Reed <Pyrohh@users.noreply.github.com>