message: [XLA] Limit the triangular solve block size to the input size. It's pointless to pad a tiny matrix (e.g., 1x1 or 2x2) out to 128x128.
diff: @@ -403,6 +403,9 @@ XlaOp BuildTriangularSolve(XlaOp a, XlaOp b, bool left_side, bool lower,
  block_size);
  }
  + block_size = std::max(
  + int64{1}, std::min(block_size, ShapeUtil::GetDimension(a_shape, -1)));
  +
  if (ShapeUtil::IsZeroElementArray(b_shape)) {
  // The output has the same shape as 'b', and since the output has zero
  // elements, any such array will do.
  