By Patricia Zengerle WASHINGTON (Reuters) -The U.S. Senate backed a defense policy bill authorizing a record $886 billion in annual military spending with strong support from both Democrats and Republicans on Wednesday, sidestepping partisan divides over social issues that had threatened what is seen as a must-pass bill. Separate from the appropriations bills that set government spending levels, the National Defense Authorization Act, or NDAA, authorizes everything from pay raises for the troops – this year’s will be 5.2% – to purchases of ships, ammunition and aircraft as well as policies suc…