Reland "[turbofan] Instruction scheduler for Turbofan."

src/compiler/ppc/instruction-scheduler-ppc.cc

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/compiler/instruction-scheduler.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+bool InstructionScheduler::SchedulerSupported() { return false; }
+
+
+int InstructionScheduler::GetTargetInstructionFlags(
+    const Instruction* instr) const {
+  UNIMPLEMENTED();
+}
+
+
+int InstructionScheduler::GetInstructionLatency(const Instruction* instr) {
+  UNIMPLEMENTED();
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8