This can be useful to make sure that a project builds when
its fallbacks are used on systems where external dependencies
satisfy the version requirements, or to easily hack on the sources
of a dependency for which a fallback exists.

Add some missing statements to list of keywords
Derive from prog-mode, so any prog-mode hooks are run
Automatically use this mode for meson.build files

[ci skip]

false || { rc=$?; echo $rc; exit $rc } || :

Exits current shell without possibility to prevent that.

Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>

The zsh completion script is explicitly licensed to eliminate
any legal obstacles for its co-distribution with Z Shell itself.