[AMDGPU] Use LV wrapperPass in getAnalysisUsage.

Author: cdevadas

Diff for: llvm/lib/Target/AMDGPU/SILowerControlFlow.cpp

@@ -152,7 +152,7 @@ class SILowerControlFlow : public MachineFunctionPass {
     AU.addPreserved<MachineDominatorTreeWrapperPass>();
     AU.addPreserved<SlotIndexesWrapperPass>();
     AU.addPreserved<LiveIntervalsWrapperPass>();
-    AU.addPreservedID(LiveVariablesID);
+    AU.addPreserved<LiveVariablesWrapperPass>();
     MachineFunctionPass::getAnalysisUsage(AU);
   }
 };