message: XLA: Add comment in the HLO importer that ReshapeOp does not have dimensions
  While the reshape operation defined in the XlaBuilder takes a dimensions attribute, it's actually transformed into a transpose if necessary and the ReshapeOp does not implement dimensions.
diff: @@ -354,6 +354,10 @@ StatusOr<mlir::Operation*> HloFunctionImporter::ImportInstruction(
  NoAttributeCase(kMaximum, MaxOp);
  NoAttributeCase(kMinimum, MinOp);
  NoAttributeCase(kMultiply, MulOp);
  + // The dimensions attribute is not present on the HLO Reshape instruction.
  + // If dimensions are non-default, the XLA builder implementes it as a
  + // separate transpose.
  + NoAttributeCase(kReshape, ReshapeOp);
  NoAttributeCase(kSelect, SelectOp);
  NoAttributeCase(kSubtract, SubOp);
  NoAttributeCase(kTanh, TanhOp);
  @@ -365,7 +369,6 @@ StatusOr<mlir::Operation*> HloFunctionImporter::ImportInstruction(
  NoAttributeCase(kCopy, CopyOp);
  // TODO(b/129422361) Ops below need additional work to handle attributes.
  NoAttributeCase(kConvolution, ConvOp);
  - NoAttributeCase(kReshape, ReshapeOp);
  #undef NoAttributeCase
  #undef MakeAndReturn
  case HloOpcode::kAddDependency:
  