parser accepts " /foo x -> /bar," as valid rule

[Christian Boltz]

If you try to use a file rule like
    /foo x,
the parser complains that you need to use ix, Px, Cx etc - good.

However, if you add an exec target like
  /foo x -> /bar,
it will happily accept that rule.

Reproducer:
    echo '/t { /foo x -> /bar, }' | /sbin/apparmor_parser -pq
surprisingly accepts the rule as valid.

I'd expect that only deny rules allow to use a plain 'x':
  deny /foo x,