By Amruta Khandekar and Ankika Biswas (Reuters) – Wall Street’s main indexes jumped on Tuesday as growing evidence of cooling inflation bolstered hopes of smaller rate hikes by the Federal Reserve, while Walmart’s upbeat forecast powered gains in retail sector. Data showed U.S. producer prices increased less than expected, rising 8% in the 12 months through October against an estimated 8.3% rise, according to a Reuters poll of economists. The report follows a softer-than-expected consumer prices reading late last week, which sparked a massive rally on hopes that the Fed would tone down its agg…