If a call has a Dereferenceable parameter and the call site provides
a pointer load to that parameter, walk all load's uses and validate
that all the calls we find have at least one parameter which
shares this property and matches the same definition.
I have done this as an existence walk, but it could just as easily be an intersection
of all the loads parameters that are used in calls.
I don't understand how we can ignore non call uses but somehow need a property of call uses, I'm fairly certain a simple bitcast will break this.