message: Remove cells where now unnecessary.
diff: -use std::cell::{RefCell, RefMut, Cell, Ref};
  +use std::cell::{RefCell, RefMut};
  use std::collections::HashSet;
  use std::collections::hash_map::Entry::{Occupied, Vacant};
  use std::collections::hash_map::HashMap;
  @@ -49,11 +49,16 @@ pub struct Config {
  /// The location of the rustdoc executable
  rustdoc: LazyCell<PathBuf>,
  /// Whether we are printing extra verbose messages
  - extra_verbose: Cell<bool>,
  - frozen: Cell<bool>,
  - locked: Cell<bool>,
  + extra_verbose: bool,
  + /// TODO to do with Cargo.lock
  + frozen: bool,
  + /// TODO to do with Cargo.lock
  + locked: bool,
  + /// A global static IPC control mechanism (used for managing parallel builds)
  jobserver: Option<jobserver::Client>,
  - cli_flags: RefCell<CliUnstable>,
  + /// Cli flags of the form "-Z something"
  + cli_flags: CliUnstable,
  + /// A handle on curl easy mode for http calls
  easy: LazyCell<RefCell<Easy>>,
  }
  @@ -80,9 +85,9 @@ impl Config {
  values: LazyCell::new(),
  cargo_exe: LazyCell::new(),
  rustdoc: LazyCell::new(),
  - extra_verbose: Cell::new(false),
  - frozen: Cell::new(false),
  - locked: Cell::new(false),
  + extra_verbose: false,
  + frozen: false,
  + locked: false,
  jobserver: unsafe {
  if GLOBAL_JOBSERVER.is_null() {
  None
  @@ -90,7 +95,7 @@ impl Config {
  Some((*GLOBAL_JOBSERVER).clone())
  }
  },
  - cli_flags: RefCell::new(CliUnstable::default()),
  + cli_flags: CliUnstable::default(),
  easy: LazyCell::new(),
  }
  }
  @@ -435,28 +440,28 @@ impl Config {
  self.shell().set_verbosity(verbosity);
  self.shell().set_color_choice(color.map(|s| &s[..]))?;
  - self.extra_verbose.set(extra_verbose);
  - self.frozen.set(frozen);
  - self.locked.set(locked);
  - self.cli_flags.borrow_mut().parse(unstable_flags)?;
  + self.extra_verbose = extra_verbose;
  + self.frozen = frozen;
  + self.locked = locked;
  + self.cli_flags.parse(unstable_flags)?;
  Ok(())
  }
  - pub fn cli_unstable(&self) -> Ref<CliUnstable> {
  - self.cli_flags.borrow()
  + pub fn cli_unstable(&self) -> &CliUnstable {
  + &self.cli_flags
  }
  pub fn extra_verbose(&self) -> bool {
  - self.extra_verbose.get()
  + self.extra_verbose
  }
  pub fn network_allowed(&self) -> bool {
  - !self.frozen.get()
  + !self.frozen
  }
  pub fn lock_update_allowed(&self) -> bool {
  - !self.frozen.get() && !self.locked.get()
  + !self.frozen && !self.locked
  }
  /// Loads configuration from the filesystem
  