devel/p5-Feature-Compat-Defer: Add new port

This module provides a new syntax keyword, defer, in a
forward-compatible way.

The latest perl development source provides a defer block syntax, under
the defer named feature. If all goes well, this will become available
at development version 5.35.4, and included in the 5.36 release. On
such perls, this module simply enables that feature.

defer {
   STATEMENTS...
}

The defer keyword introduces a block which runs its code body at the
time that its immediately surrounding code block finishes.