Function process_do_while

src/completion/variable/forward_walk.rs:7152–7193

Process a `do-while` loop. Uses the same assignment-depth-bounded iteration as `process_foreach`: a cheap AST walk determines the dependency chain depth, then the body is re-walked up to that many times with fixed-point early exit. Unlike `for`/`while`, the body of a `do-while` always executes at least once, so we do NOT merge with a pre-loop scope at the end.

(dw: &'b DoWhile<'b>, scope: &mut ScopeState, ctx: &ForwardWalkCtx<'_>)

/// Unlike `for`/`while`, the body of a `do-while` always executes at
/// least once, so we do NOT merge with a pre-loop scope at the end.
fn process_do_while<'b>(dw: &'b DoWhile<'b>, scope: &mut ScopeState, ctx: &ForwardWalkCtx<'_>) {
    let loop_depth = enter_loop();

    // Hard limit: skip the body entirely at excessive nesting depth.
    if loop_depth > MAX_LOOP_DEPTH {
        leave_loop(loop_depth);
        return;
    }

    let pre_loop_scope = scope.clone();

    // ── Assignment-depth-bounded loop iteration ─────────────────
    let body_stmts: Vec<&Statement<'b>> = vec![dw.statement];
    let assignment_depth =
        clamp_iterations_for_depth(assignment_map_depth(&body_stmts), loop_depth);

    // ── Initial walk (always performed) ─────────────────────────
    walk_body_forward(std::iter::once(dw.statement), scope, ctx);

    // ── Re-walk iterations (only if types changed) ──────────────
    for _iteration in 0..assignment_depth.saturating_sub(1) {
        if !scope_has_changes(&pre_loop_scope, scope) {
            break;
        }

        let mut next_scope = pre_loop_scope.clone();
        next_scope.merge_branch(scope);
        process_condition_assignment(dw.condition, &mut next_scope, ctx);
        seed_pass_by_ref_in_condition(dw.condition, &mut next_scope, ctx);
        *scope = next_scope;

        walk_body_forward(std::iter::once(dw.statement), scope, ctx);
    }

    // After the do-while loop, the condition evaluated to false (that's
    // why the loop exited).  Apply the inverse of the condition to narrow
    // types.  For example: `do { $a = getA(); } while ($a !== null);`
    // => after loop, $a is null.
    apply_condition_narrowing_inverse(dw.condition, scope, ctx);

    leave_loop(loop_depth);
}

/// Process a `try-catch-finally` statement.
fn process_try<'b>(try_stmt: &'b Try<'b>, scope: &mut ScopeState, ctx: &ForwardWalkCtx<'_>) {