message: [XLA] Speed up exhaustive_f32_elementwise_op_test.
  This was spending the majority of its time in Literal::Get() and
  Literal::Set().
  Before: 2.5s to run a shard.
  After:  1.0s to run a shard.
diff: @@ -40,14 +40,15 @@ class ExhaustiveF32ElementwiseOpTest
  Literal input_literal =
  LiteralUtil::CreateFromDimensions(F32, {input_size});
  + absl::Span<float> input_arr = input_literal.data<float>();
  for (int64 i = begin; i < end; i++) {
  if (i >= known_incorrect_range.first &&
  i < known_incorrect_range.second) {
  // If the operation is known to be buggy on a specific input clamp that
  // input to 0 under the assumption that the op is at least correct on 0.
  - input_literal.Set({i - begin}, 0.0f);
  + input_arr[i - begin] = 0;
  } else {
  - input_literal.Set({i - begin}, absl::bit_cast<float, int>(i));
  + input_arr[i - begin] = absl::bit_cast<float, int>(i);
  }
  }
  @@ -60,7 +61,7 @@ class ExhaustiveF32ElementwiseOpTest
  std::vector<float> expected_result;
  expected_result.reserve(input_size);
  for (int64 i = 0; i < input_size; i++) {
  - expected_result.push_back(evaluate_op(input_literal.Get<float>({i})));
  + expected_result.push_back(evaluate_op(input_arr[i]));
  }
  ComputeAndCompareR1<float>(&builder, expected_result, {input_data.get()},
  