Function scope_has_changes

src/completion/variable/forward_walk.rs:6084–6106

Check whether the post-walk scope has any NEW or CHANGED variable types compared to the pre-loop scope. This is the Mago-style fixed-point check that runs BEFORE a re-walk: if nothing changed, there's no point walking the body again. Unlike `scopes_equal`, this is asymmetric: new variables in `after` that weren't in `before` count as changes, but variables in `before` that aren't in `after` do n

(before: &ScopeState, after: &ScopeState)

/// in `before` that aren't in `after` do not (they were just not
/// assigned in the loop body).
fn scope_has_changes(before: &ScopeState, after: &ScopeState) -> bool {
    for (name, after_types) in &after.locals {
        match before.locals.get(name) {
            None => {
                // New variable assigned in the loop body.
                if !after_types.is_empty() {
                    return true;
                }
            }
            Some(before_types) => {
                if after_types.len() != before_types.len() {
                    return true;
                }
                for (at, bt) in after_types.iter().zip(before_types.iter()) {
                    if at.type_string != bt.type_string {
                        return true;
                    }
                }
            }
        }
    }
    false
}

/// Process a `foreach` statement.
fn process_foreach<'b>(foreach: &'b Foreach<'b>, scope: &mut ScopeState, ctx: &ForwardWalkCtx<'_>) {