Add a use of an otherwise unused variable to remove a warning in non-Asserts

builds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175981 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/TwoAddressInstructionPass.cpp

@@ -1220,6 +1220,7 @@ tryInstructionTransform(MachineBasicBlock::iterator &mi,
         MachineBasicBlock::iterator NewMI = NewMIs[1];
         bool TransformResult =
           tryInstructionTransform(NewMI, mi, NewSrcIdx, NewDstIdx, Dist, true);
+        (void)TransformResult;
         assert(!TransformResult &&
                "tryInstructionTransform() should return false.");
         if (NewMIs[1]->getOperand(NewSrcIdx).isKill()) {