Merged requested to merge Blaisorblade/stdpp:set_bind into master
This is @dfrumin's !383 (closed) (with authorship preserved) + some tweaks to setoid rewriting:
- strengthen set_bind_subset to have the same arity
- add missing Params instance to prevent slow failures in setoid rewriting
Properinstances can be proven before
set_bind_extis then provable by set_solver directly.
I originally sent dfrumin/coq-stdpp!1 (closed) to be added into !383 (closed), but maybe it's easier with this MR? @robbertkrebbers up to you.