The Nikkei stock index ended at a 34-year high Thursday as exporter issues were boosted by a weakening yen against the U.S. dollar after Bank of Japan Deputy Governor Shinichi Uchida hinted the bank will maintain its accommodative policy stance even after ending negative rates. The 225-issue Nikkei Stock Average ended up 743.36 points, or 2.06 percent, from Wednesday at 36,863.28, its highest level since February 1990. The broader Topix index finished 12.68 points, or 0.50 percent, higher at 2,562.63, also the highest level since February 1990. On the top-tier Prime Market, gainers were led by…