Revert "Fixing a bug in QPE: integer power within a while loop"

  // 'After' block must end with a yield op.

  {

    mlir::OpBuilder::InsertionGuard g(builder);

    if (auto b = symbol_table.get_last_created_block()) {

      builder.setInsertionPointToEnd(b);

      symbol_table.set_last_created_block(nullptr);

    } else {

    mlir::Operation &lastOp = whileOp.after().front().getOperations().back();

    builder.setInsertionPointAfter(&lastOp);

    }

    builder.create<mlir::scf::YieldOp>(location);

  }