type: Stop claiming `grep` is a function

Use `functions -q` instead of searching the `functiosn -na` list for the
provided word. This may result in an automatically-loaded function being
sourced, but that happens anyway with the default output.

This change means the results of `test -q foo` can be relied upon to
indicate whether `foo` can actually be invoked. Previosly, if `foo` was
the name of an automatically-loaded function file but did not actually
define a function `foo`, and there was no execuable `foo`, then `type -q
foo` would lie and say `foo` can be invoked when it can't.

0 files changed, 0 insertions, 0 deletions