message: custom-named-profiles: predefined check profile
  Since we also for 'cargo rustc' to received '--profile check', let
  it be consistent with the other commands and use a predefined 'check'
  profile for it that inherits from "dev".
  Fixes tests check::rustc_check and check::rustc_check_err.
diff: @@ -77,6 +77,7 @@ impl Profiles {
  fn predefined_dir_names() -> BTreeMap<String, String> {
  let mut dir_names = BTreeMap::new();
  dir_names.insert("dev".to_owned(), "debug".to_owned());
  + dir_names.insert("check".to_owned(), "debug".to_owned());
  dir_names.insert("test".to_owned(), "debug".to_owned());
  dir_names.insert("bench".to_owned(), "release".to_owned());
  dir_names
  @@ -112,6 +113,10 @@ impl Profiles {
  inherits: Some(String::from("dev")),
  ..TomlProfile::default()
  }),
  + ("check", TomlProfile {
  + inherits: Some(String::from("dev")),
  + ..TomlProfile::default()
  + }),
  ]
  }
  