Revert "blockfreq: Rewrite BlockFrequencyInfoImpl" (#2)

This reverts commit r206666, as planned.

Still stumped on why the bots are failing.  Sanitizer bots haven't
turned anything up.  If anyone can help me debug either of the failures
(referenced in r206666) I'll owe them a beer.  (In the meantime, I'll be
auditing my patch for undefined behaviour.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206677 91177308-0d34-0410-b5e6-96231b3b80d8

Author: dexonsmith

include/llvm/Analysis/BlockFrequencyInfoImpl.h

@@ -11,7 +11,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "block-freq"
 #include "llvm/Analysis/BlockFrequencyInfo.h"
 #include "llvm/Analysis/BlockFrequencyInfoImpl.h"
 #include "llvm/Analysis/BranchProbabilityInfo.h"
@@ -107,7 +106,6 @@ struct DOTGraphTraits<BlockFrequencyInfo*> : public DefaultDOTGraphTraits {
 INITIALIZE_PASS_BEGIN(BlockFrequencyInfo, "block-freq",
                       "Block Frequency Analysis", true, true)
 INITIALIZE_PASS_DEPENDENCY(BranchProbabilityInfo)
-INITIALIZE_PASS_DEPENDENCY(LoopInfo)
 INITIALIZE_PASS_END(BlockFrequencyInfo, "block-freq",
                     "Block Frequency Analysis", true, true)
 
@@ -122,16 +120,14 @@ BlockFrequencyInfo::~BlockFrequencyInfo() {}
 
 void BlockFrequencyInfo::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<BranchProbabilityInfo>();
-  AU.addRequired<LoopInfo>();
   AU.setPreservesAll();
 }
 
 bool BlockFrequencyInfo::runOnFunction(Function &F) {
   BranchProbabilityInfo &BPI = getAnalysis<BranchProbabilityInfo>();
-  LoopInfo &LI = getAnalysis<LoopInfo>();
   if (!BFI)
     BFI.reset(new ImplType);
-  BFI->doFunction(&F, &BPI, &LI);
+  BFI->doFunction(&F, &BPI);
 #ifndef NDEBUG
   if (ViewBlockFreqPropagationDAG != GVDT_None)
     view();
@@ -162,7 +158,7 @@ void BlockFrequencyInfo::view() const {
 }
 
 const Function *BlockFrequencyInfo::getFunction() const {
-  return BFI ? BFI->getFunction() : nullptr;
+  return BFI ? BFI->Fn : nullptr;
 }
 
 raw_ostream &BlockFrequencyInfo::