message: Remove second parameter of subspan call.
  By default it will select the remainder of the span, anyway. Also, on the first
  glance the value operands.size() for length looks wrong (although subspan clamps it at operands.size() / 2 so this is not a bug).
diff: @@ -1089,8 +1089,8 @@ bool HloParser::ParseInstruciontRhs(HloComputation::Builder* builder,
  absl::Span<HloInstruction* const>(operands).subspan(
  0, operands.size() / 2),
  /*init_values=*/
  - absl::Span<HloInstruction* const>(operands).subspan(
  - operands.size() / 2, operands.size()),
  + absl::Span<HloInstruction* const>(operands).subspan(operands.size() /
  + 2),
  *dimensions_to_reduce, *reduce_computation));
  break;
  }
  