message: Don't pass RUSTFLAGS to rustc in tests
diff: @@ -425,7 +425,6 @@ fn rustc_command<I, S>(&self, args: I) -> Command
  cmd.arg(format!("{}", self.out_dir.display()));
  cmd.arg("-Cdebuginfo=2");
  cmd.args(args);
  - cmd.env("RUSTFLAGS", &self.rust_flags);
  cmd
  }
  