putfield <o.f:bar>: pop the pointer reference to an object of class bar off the stack and set the f field .
- When the class was loaded o.f:bar was added to the assumption set. When o is loaded this assumption will be checked.
- Check that each t?top(l) is in RefTy.
- For each t?top(l) add t ? o to the assumption set.
- For each t?top(pop(l)) add t ? bar to the assumption set.
- example: foo1 ? bar, foo2 ? bar,