[BPI] Apply invoke heuristic before loop branch heuristic

Currently the loop branch heuristic is applied before the invoke heuristic which makes us overestimate the probability of the unwind destination of invokes inside loops. This in turn makes us grossly underestimate the frequencies of loops with invokes.

Reviewed By: skatkov, vsk

Differential Revision: https://reviews.llvm.org/D47371

llvm-svn: 334285