(Reuters) - Britain's stock markets dived for the eighth day in 10 on Wednesday, as more companies warned of a severe hit to earnings from the coronavirus pandemic even as policymakers pushed for fresh stimulus measures to support global growth.The blue-chip FTSE 100 fell 4.7%, with Boeing supplier Meggit , aero-engines maker Rolls-Royce dropping 22.5% and 14.2%, respectively, as evidence grew of the profound damage the crisis is doing to global airlines.U.S. investment bank JPMorgan said it..