If parallelization for FuTIL lowering.

[cgyurgyik]

decl A: ubit<32>[1];
let x: ubit<32> = 0;

if (x == 0) { x := 2; }
A[0] := x; // Holds zero :-(

A[0] will still hold value 0 instead of 2. However, it works fine in the following cases:

decl A: ubit<32>[1];
let x: ubit<32> = 0;

if (x == 0) { x := 2; } else { x := x; }
A[0] := x; // Holds 2!

decl A: ubit<32>[1];
let x: ubit<32> = 0;

if (x == 0) { x := 2; } 
---
A[0] := x; // Holds 2!

@sgpthomas Noted that since the if writes to x, it should be sequenced with the read from x.

[sampsyo]

Just wanted to say this is a model bug report. Minimal but independently-compilable examples, including expected vs. actual output. Wahoo! 🙌