[turbofan] Initial attempt to cleanup Node and related classes.

src/compiler/node-properties.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/common-operator.h"
+#include "src/compiler/node-properties.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+Node* NodeProperties::FindProjection(Node* node, size_t projection_index) {
+  for (auto use : node->uses()) {
+    if (use->opcode() == IrOpcode::kProjection &&
+        ProjectionIndexOf(use->op()) == projection_index) {
+      return use;
+    }
+  }
+  return nullptr;
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8