Remove an incorrect assert during branch weight propagation.

Patch and test case by Alastair Murray!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163437 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Utils/SimplifyCFG.cpp

@@ -929,7 +929,6 @@ bool SimplifyCFGOpt::FoldValueComparisonIntoPredecessors(TerminatorInst *TI,
                                 GetWeight(TI, i)->getValue().getZExtValue());
             } else if (PredHasWeights) {
               // Split the old default's weight amongst the children
-              assert(PredDefaultWeight != 0);
               Weights.push_back(PredDefaultWeight / (1 + BBCases.size()));
             }
           }