Fix overflow in add_dpbusd_epi32x2

[nodchip]

Stockfish の

• https://github.com/official-stockfish/Stockfish/commit/564456a6a824bfca26d6d9af5b35a055eb9fc6c2

• https://github.com/official-stockfish/Stockfish/commit/2c36d1e7e7374b8babb3cc503c0bc07ceb83dbf8

  をマージするためのプルリクエストです。 nps は変更前と変更後で以下のように変化しています。

変更前

===========================
Total time (ms) : 60004
Nodes searched  : 77916762
Nodes_searched/second    : 1298526
===========================

===========================
Total time (ms) : 60029
Nodes searched  : 78165853
Nodes_searched/second    : 1302134
===========================

===========================
Total time (ms) : 60006
Nodes searched  : 78021690
Nodes_searched/second    : 1300231
===========================

変更後

===========================
Total time (ms) : 60008
Nodes searched  : 77163881
Nodes_searched/second    : 1285893
===========================

===========================
Total time (ms) : 60004
Nodes searched  : 78026514
Nodes_searched/second    : 1300355
===========================

===========================
Total time (ms) : 60005
Nodes searched  : 77763262
Nodes_searched/second    : 1295946
===========================

計測は、 標準 NNUE (halfkp_256x2-32-32) 評価関数『Háo』を用いて行いました。

よろしくお願いいたします。

[yaneurao]

ありがとうございます!!