Match statements do not propagate control flow

[livia01px2019]

Paralegal doesn't correctly propagate control flow relations when match statements are involved.

This is causing the Atomic property to fail: the add_resource_opts call here does not see the control-flow influence from the check_write call here due to the fact that it is wrapped in an if let.

Consider the following minimal examples:

#[paralegal::analyze]
pub fn minimal_match(&self, i: AtomicResult<i64>, j: i64, k: bool) {
    if self.is_ok(j).is_ok() {
        match Some(k) {
            Some(k) => self.store(j),
            None => (),
        };
    }
}

#[paralegal::analyze]
pub fn minimal_no_match(&self, i: AtomicResult<i64>, j: i64, k: bool) {
    if self.is_ok(j).is_ok() {
        if k {
            self.store(j);
        }
    }
}

We expect that in both examples is_ok has control-flow influence on store. However, these are the corresponding graphs:

With match:
minimal_match_76201e.inlined-pruned.gv.pdf

Without match:
minimal_no_let_a24bcc.inlined-pruned.gv.pdf

With match, there is no control-flow influence anywhere.

Here is the MIR for the code with the match -- I believe the control-flow influence is there, but it's not captured in our SPDG.
minimal_match.mir.gv.pdf