Access to a slice pointer should yield access to its cells

[jcp19]

In a conversation with @Felalolf, we came to the idea that acc(s) should yield access to all s's cells when s is of pointer to slice type, i.e. *[]T, for arbitrary T. This would be consistent with what is done for pointers to structs and its fields.

[jcp19]

this is a simple addition with the changes I introduced in the add-maps branch. I will add this after that branch is merged

[jcp19]

Right now, he are using a heap-dependent triggers, which are not ideal. I will fix it