revert r89298, which was committed without a testcase. I think

the underlying PHI node insertion issue in SSAUpdate is fixed.

llvm-svn: 91821

llvm/lib/Transforms/Utils/LoopSimplify.cpp

@@ -305,12 +305,6 @@ ReprocessLoop:
     }
   }
 
-  // If there are duplicate phi nodes (for example, from loop rotation),
-  // get rid of them.
-  for (Loop::block_iterator BB = L->block_begin(), E = L->block_end();
-       BB != E; ++BB)
-    EliminateDuplicatePHINodes(*BB);
-
   return Changed;
 }