Disable again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133446 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TailDuplication.cpp b/lib/CodeGen/TailDuplication.cpp
index 2d89f71..d16369a 100644
--- a/lib/CodeGen/TailDuplication.cpp
+++ b/lib/CodeGen/TailDuplication.cpp
@@ -712,7 +712,7 @@
   DenseSet<unsigned> UsedByPhi;
   getRegsUsedByPHIs(*TailBB, &UsedByPhi);
 
-  if (isSimpleBB(TailBB))
+  if (0 && isSimpleBB(TailBB))
     return duplicateSimpleBB(TailBB, TDBBs, UsedByPhi, Copies);
 
   // Iterate through all the unique predecessors and tail-duplicate this