message: perf(es/minifier): Make the expression simplifier more parallel
  **Description:**
  It was not parallel enough.
diff: @@ -98,7 +98,7 @@ impl Repeated for SimplifyExpr {
  }
  impl SimplifyExpr {
  - fn fold_member_expr(&mut self, expr: &mut Expr) {
  + fn optimize_member_expr(&mut self, expr: &mut Expr) {
  let MemberExpr { obj, prop, .. } = match expr {
  Expr::Member(member) => member,
  _ => return,
  @@ -327,7 +327,7 @@ impl SimplifyExpr {
  }
  }
  - fn fold_bin(&mut self, expr: &mut Expr) {
  + fn optimize_bin_expr(&mut self, expr: &mut Expr) {
  let BinExpr {
  left,
  op,
  @@ -741,7 +741,7 @@ impl SimplifyExpr {
  }));
  }
  - fn fold_unary(&mut self, expr: &mut Expr) {
  + fn optimize_unary_expr(&mut self, expr: &mut Expr) {
  let UnaryExpr { op, arg, span } = match expr {
  Expr::Unary(unary) => unary,
  _ => return,
  @@ -1296,16 +1296,16 @@ impl VisitMut for SimplifyExpr {
  match expr {
  Expr::Unary(_) => {
  - self.fold_unary(expr);
  + self.optimize_unary_expr(expr);
  debug_assert_valid(expr);
  }
  Expr::Bin(_) => {
  - self.fold_bin(expr);
  + self.optimize_bin_expr(expr);
  debug_assert_valid(expr);
  }
  Expr::Member(_) => {
  - self.fold_member_expr(expr);
  + self.optimize_member_expr(expr);
  debug_assert_valid(expr);
  }
  @@ -1421,7 +1421,9 @@ impl VisitMut for SimplifyExpr {
  in_callee: Default::default(),
  };
  - n.visit_mut_children_with(&mut child);
  + child.maybe_par(cpu_count() * 8, n, |v, n| {
  + n.visit_mut_with(v);
  + });
  self.changed |= child.changed;
  }
  @@ -1562,7 +1564,9 @@ impl VisitMut for SimplifyExpr {
  in_callee: Default::default(),
  };
  - n.visit_mut_children_with(&mut child);
  + child.maybe_par(cpu_count() * 8, n, |v, n| {
  + n.visit_mut_with(v);
  + });
  self.changed |= child.changed;
  }
  