message: Don't compare `ExpectedSyscall` using `PartialEq`, use `matches!` instead.
  `ExpectedSyscall` no longer implements `PartialEq` because its semantics are a bit unclear/fuzzy (especially with an expected `Command`). This broke the tests for the expected syscall queue. This PR changes the expected syscall queue tests to use pattern matching to check the value instead.
diff: @@ -131,33 +131,34 @@ mod tests {
  #[test]
  fn expected_syscall_queue() {
  use libtock_platform::YieldNoWaitReturn::Upcall;
  + use std::matches;
  use ExpectedSyscall::{YieldNoWait, YieldWait};
  let kernel = Kernel::new();
  - assert_eq!(kernel.pop_expected_syscall(), None);
  + assert!(matches!(kernel.pop_expected_syscall(), None));
  kernel.add_expected_syscall(YieldNoWait {
  override_return: None,
  });
  kernel.add_expected_syscall(YieldNoWait {
  override_return: Some(Upcall),
  });
  - assert_eq!(
  + assert!(matches!(
  kernel.pop_expected_syscall(),
  Some(YieldNoWait {
  override_return: None
  })
  - );
  + ));
  kernel.add_expected_syscall(YieldWait { skip_upcall: false });
  - assert_eq!(
  + assert!(matches!(
  kernel.pop_expected_syscall(),
  Some(YieldNoWait {
  override_return: Some(Upcall)
  })
  - );
  - assert_eq!(
  + ));
  + assert!(matches!(
  kernel.pop_expected_syscall(),
  Some(YieldWait { skip_upcall: false })
  - );
  - assert_eq!(kernel.pop_expected_syscall(), None);
  + ));
  + assert!(matches!(kernel.pop_expected_syscall(), None));
  }
  #[test]
  