At least 36 of the 100-largest U.S. prime money-market funds had to be propped up in order to survive the financial crisis, according to a report from Moody’s Investors Service. From August 2007 to December 2009, at least 20 firms that manage such funds in the U.S. and Europe pumped more than $12 billion combined into their funds, according to the Moody’s Corp. unit. The lifelines included purchases of troubled securities and capital contributions.