GLOBAL MARKETS-Shares slide on fear trade spat morphs to a tech cold war

(Adds close of U.S. markets)* Dollar hits two-year high, safe-haven yen also gains* Government debt yields tumble on growth worries, trade fears* Oil extends losses, biggest decline in six months* World FX rates in 2019 http://tmsnrt.rs/2egbfVhBy Herbert LashNEW YORK, May 23 (Reuters) - World shares skidded further on Thursday and oil prices plunged more than 5% as investors worried the China-U.S.