Add some checks that got lost in the shuffle. This fixes 464.h264ref.

llvm-svn: 53760

llvm/lib/Transforms/Utils/BasicBlockUtils.cpp

@@ -39,6 +39,10 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock* BB, Pass* P) {
   
   // Can't merge if there are multiple predecessors.
   if (!PredBB) return false;
+  // Don't break self-loops.
+  if (PredBB == BB) return false;
+  // Don't break invokes.
+  if (isa<InvokeInst>(PredBB->getTerminator())) return false;
   
   succ_iterator SI(succ_begin(PredBB)), SE(succ_end(PredBB));
   BasicBlock* OnlySucc = BB;