message: Windows lock primitives: check that we are truly sinle-threaded
diff: @@ -236,12 +236,14 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  | "LeaveCriticalSection"
  | "DeleteCriticalSection" if this.frame().instance.to_string().starts_with("std::sys::windows::")
  => {
  + assert_eq!(this.get_total_thread_count()?, 1, "concurrency on Windows not supported");
  // Nothing to do, not even a return value.
  // (Windows locks are reentrant, and we have only 1 thread,
  // so not doing any futher checks here is at least not incorrect.)
  }
  "TryEnterCriticalSection" if this.frame().instance.to_string().starts_with("std::sys::windows::")
  => {
  + assert_eq!(this.get_total_thread_count()?, 1, "concurrency on Windows not supported");
  // There is only one thread, so this always succeeds and returns TRUE
  this.write_scalar(Scalar::from_i32(1), dest)?;
  }
  