auto get_then_result = [&](int i) { return call_op->getResult(i); };
  JumpToBlock(loc, get_then_result, merge_block, &builder);

  // Set up the 'else' block.
  Block* else_block = builder.createBlock(merge_block);
  call_op = CallFn(loc, get_operand, op.else_function(), &builder);

  auto get_else_result = [&](int i) { return call_op->getResult(i); };
  JumpToBlock(loc, get_else_result, merge_block, &builder);