[dfmc,dylan] Remove usage of partial-dispatch engine node in value comparison.

This is probably a performance hit, but partial dispatch is going away,
so remove this for now.
[dfmc,dylan] Remove partial dispatch.

This isn't enabled usually and isn't a clear win for performance
and costs extra space.

Let's remove it to simplify.
Merge pull request #812 from waywardmonkeys/remove-partial-dispatch

Remove partial dispatch