mem2reg ignores terminator

[joss-aztec]

Aim

SSA store/load instructions to a reference appearing in a return terminator should be preserved.

Expected Behavior

fn main(x : Field) -> pub [Field; 2] {
    [x, x]
}

should produce a valid program

Bug

Last two SSA pass ouputs

After Flattening:
fn main f1 {
  b0(v0: Field):
    v1 = alloc 2 fields
    store v0 at v1
    v3 = add v1, Field 1
    store v0 at v3
    return v1
}

After Mem2Reg:
fn main f1 {
  b0(v0: Field):
    v1 = alloc 2 fields
    v3 = add v1, Field 1
    return v1
}

Notice both stores have been removed

To Reproduce

Installation Method

None

Nargo Version

No response

Additional Context

No response

Would you like to submit a PR for this Issue?

No

Support Needs

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