Revert "Fix a quadratic algorithm in MachineBranchProbabilityInfo."

It caused an assertion failure when compiling consumer-typeset.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161463 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 2ba414d..f361d1a 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -912,11 +912,12 @@
 
 /// getSuccWeight - Return weight of the edge from this block to MBB.
 ///
-uint32_t MachineBasicBlock::getSuccWeight(const_succ_iterator Succ) const {
+uint32_t MachineBasicBlock::getSuccWeight(const MachineBasicBlock *succ) const {
   if (Weights.empty())
     return 0;
 
-  return *getWeightIterator(Succ);
+  const_succ_iterator I = std::find(Successors.begin(), Successors.end(), succ);
+  return *getWeightIterator(I);
 }
 
 /// getWeightIterator - Return wight iterator corresonding to the I successor