message: [MLIR] Add MergeSummary to TF generated ops.
  This will allow the op to be correctly inferred as having no side effects.
diff: @@ -5818,6 +5818,30 @@ def TF_MaximumOp : TF_Op<"Maximum", [NoSideEffect, ResultsBroadcastableShape, TF
  TF_DerivedOperandTypeAttr T = TF_DerivedOperandTypeAttr<0>;
  }
  +def TF_MergeSummaryOp : TF_Op<"MergeSummary", [NoSideEffect, SameOperandsAndResultType]> {
  + let summary = "Merges summaries.";
  +
  + let description = [{
  +This op creates a
  +[`Summary`](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/core/framework/summary.proto)
  +protocol buffer that contains the union of all the values in the input
  +summaries.
  +
  +When the Op is run, it reports an `InvalidArgument` error if multiple values
  +in the summaries to merge use the same tag.
  + }];
  +
  + let arguments = (ins
  + Variadic<TF_StrTensor>:$inputs
  + );
  +
  + let results = (outs
  + TF_StrTensor:$summary
  + );
  +
  + TF_DerivedOperandSizeAttr N = TF_DerivedOperandSizeAttr<0>;
  +}
  +
  def TF_MergeV2CheckpointsOp : TF_Op<"MergeV2Checkpoints", []> {
  let summary = [{
  V2 format specific: merges the metadata files of sharded checkpoints. The
  