[Turbofan] run load elimination concurrently.

src/compiler/graph-reducer.cc

 // Copyright 2014 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 <functional>
 #include <limits>
 
 #include "src/compiler/graph.h"
 #include "src/compiler/graph-reducer.h"
 #include "src/compiler/node.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/verifier.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 enum class GraphReducer::State : uint8_t {
   kUnvisited,
   kRevisit,
   kOnStack,
   kVisited
 };
 
 
 void Reducer::Finalize() {}
 
-
 GraphReducer::GraphReducer(Zone* zone, Graph* graph, Node* dead)
     : graph_(graph),
       dead_(dead),
       state_(graph, 4),
       reducers_(zone),
       revisit_(zone),
-      stack_(zone) {}
-
+      stack_(zone) {
+  if (dead != nullptr) {
+    NodeProperties::SetType(dead_, Type::None());
+  }
+}
 
 GraphReducer::~GraphReducer() {}
 
 
 void GraphReducer::AddReducer(Reducer* reducer) {
   reducers_.push_back(reducer);
 }
 
 
 void GraphReducer::ReduceNode(Node* node) {
@@ skipping 237 matching lines @@
 void GraphReducer::Revisit(Node* node) {
   if (state_.Get(node) == State::kVisited) {
     state_.Set(node, State::kRevisit);
     revisit_.push(node);
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8