LowerSubregs should not clobber any analysis.

llvm-svn: 51933

llvm/lib/CodeGen/LowerSubregs.cpp

@@ -30,6 +30,10 @@ namespace {
       return "Subregister lowering instruction pass";
     }
 
+    void getAnalysisUsage(AnalysisUsage &AU) const {
+      AU.setPreservesAll();
+    }
+
     /// runOnMachineFunction - pass entry point
     bool runOnMachineFunction(MachineFunction&);