Better scoring for loop breakers; fixes simplifier loop in nofib/minimax
See Note [Inline candidates] in OccurAnal. We were getting a recursive loop exposed, which led to infinite inlinings. Doesn't bite much, but was obviously wrong. I've change the "scoring order" for loop breakers, which could possibly have a performance impact on other programs. A full nofib run exposed a 0.00% change in allocation in any nofib program, so I don't think it's likely, but keep an eye out.