[turbofan] Also run MachineOperatorReducer in SimplifiedLoweringPhase.
[turbofan] Also run MachineOperatorReducer in SimplifiedLoweringPhase.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/809313002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#25874}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh