API to access dominated uses.

[xlauko]

Prerequisites

• I have read the documentation and the proposed feature is not implemented.

Description

Provide an API that, given an assignment to a variable produces upcoming reads of that variable.

The simplest solution would be to get all variable references and filter only those dominated by the assignment.

To detect only reads we would need to know the semantics of all operations that can operate with variable references, this can be left up to the user.

However, a more conceptual solution would need us to build a dependence graph and consider dominance.

Also, note that a read can precede the assignment in case of loops.