SINGAPORE (Reuters) - U.S. Treasuries extended heavy losses on Wednesday in a sign investors are selling even their safest assets as a global market rout unleashed by U.S. tariffs takes an unnerving turn towards distress and a dash for the safety of cash. "This is beyond fundamentals right now. This is about liquidity," said Jack Chambers, senior rates strategist at ANZ in Sydney. The 10-year U.S. Treasury yield, the globe's benchmark safe-haven anchor, was up 20 basis points and rising in Asia - a remarkable move in a time zone where it's usually fairly steady. At 4.46% the yield is...