Revert "Initial implementation of optimization bisect support."

This reverts commit r267022, due to an ASan failure:

  http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/1549

llvm-svn: 267115
diff --git a/llvm/lib/Transforms/Scalar/DCE.cpp b/llvm/lib/Transforms/Scalar/DCE.cpp
index a1f2ecf..b67c3c7 100644
--- a/llvm/lib/Transforms/Scalar/DCE.cpp
+++ b/llvm/lib/Transforms/Scalar/DCE.cpp
@@ -41,7 +41,7 @@
       initializeDeadInstEliminationPass(*PassRegistry::getPassRegistry());
     }
     bool runOnBasicBlock(BasicBlock &BB) override {
-      if (skipBasicBlock(BB))
+      if (skipOptnoneFunction(BB))
         return false;
       auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();
       TargetLibraryInfo *TLI = TLIP ? &TLIP->getTLI() : nullptr;
@@ -122,7 +122,7 @@
 }
 
 bool DCE::runOnFunction(Function &F) {
-  if (skipFunction(F))
+  if (skipOptnoneFunction(F))
     return false;
 
   auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();