Salesforce shares CRM.N soared 24.1%. By Herbert Lash NEW YORK, Aug 26 (Reuters) - A gauge of global equity markets jumped to an all-time peak on Wednesday, after the S&P 500 and Nasdaq rallied to fresh records on upbeat corporate results, while the dollar eased a day before the Federal Reserve potentially sets a new course on inflation. Investors are focused on whether Federal Reserve Chairman Jerome Powell will hint at shifting the Fed's inflation target to an average when he addresses the U.S. central bank's policy framework review at the Jackson Hole symposium on Thursday.