Re-commit optimization bisect support (r267022) without new pass manager support.

The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267231
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index ea1325a..e34233a 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -211,7 +211,7 @@
 }
 
 bool CodeGenPrepare::runOnFunction(Function &F) {
-  if (skipOptnoneFunction(F))
+  if (skipFunction(F))
     return false;
 
   DL = &F.getParent()->getDataLayout();