message: Validate `proto.dtype()` before calling `set_dtype()`.
  This prevents a `DCHECK`-fail when the proto contains an invalid dtype for a tensor shape with 0 elements or for an incomplete tensor shape.
diff: @@ -939,6 +939,15 @@ bool Tensor::FromProto(Allocator* a, const TensorProto& proto) {
  dtype_error = true, dtype_error = true);
  }
  if (dtype_error || p == nullptr) return false;
  + } else {
  + // Handle the case of empty tensors (N = 0) or tensors with incomplete shape
  + // (N = -1). All other values of `shape.num_elements()` should be invalid by
  + // construction.
  + // Here, we just need to validate that the `proto.dtype()` value is valid.
  + bool dtype_error = false;
  + CASES_WITH_DEFAULT(proto.dtype(), break, dtype_error = true,
  + dtype_error = true);
  + if (dtype_error) return false;
  }
  shape_ = shape;
  set_dtype(proto.dtype());
  