message: Fixed compile failing because Resolve::features() no longer returns an Option.
diff: @@ -639,16 +639,13 @@ impl<'a, 'cfg> Context<'a, 'cfg> {
  // Integration tests/benchmarks require binaries to be built
  if unit.profile.test &&
  (unit.target.is_test() || unit.target.is_bench()) {
  - let no_features = HashSet::new();
  - let features = self.resolve.features(id).unwrap_or(&no_features);
  -
  ret.extend(unit.pkg.targets().iter().filter(|t| {
  let no_required_features = Vec::new();
  t.is_bin() &&
  // Skip binaries with required features that have not been selected.
  t.required_features().unwrap_or(&no_required_features).iter().all(|f| {
  - features.contains(f)
  + self.resolve.features(id).contains(f)
  })
  }).map(|t| {
  Unit {
  