pub fn linear_scan_assignment(spec: &RegSpec) -> Vec<Option<usize>>Expand description
A deterministic linear-scan assignment: variable index i → the physical register it is given, or
None if linear-scan must spill it (no register was free when it became live). This is the data
the animated view replays — each variable becomes one bar that lights up in its register’s lane
while it is live. Re-checkable via is_valid_linear_scan. It spills nothing exactly when the
block fits the budget (peak pressure ≤ registers), so it agrees with the certified allocate
decision while also showing which value gets evicted when it does not.