[turbofan] Run everything after representation selection concurrently.

src/compiler/js-graph.cc

Index: src/compiler/js-graph.cc
diff --git a/src/compiler/js-graph.cc b/src/compiler/js-graph.cc
index 1c5b1824fea5e26b999462172136465a9274ea56..7def9a82ca65e3835473d81836aa7133840d92d3 100644
--- a/src/compiler/js-graph.cc
+++ b/src/compiler/js-graph.cc
@@ -14,6 +14,15 @@ namespace compiler {
 #define CACHED(name, expr) \
   cached_nodes_[name] ? cached_nodes_[name] : (cached_nodes_[name] = (expr))
 
+Node* JSGraph::AllocateInNewSpaceStubConstant() {
+  return CACHED(kAllocateInNewSpaceStubConstant,
+                HeapConstant(isolate()->builtins()->AllocateInNewSpace()));
+}
+
+Node* JSGraph::AllocateInOldSpaceStubConstant() {
+  return CACHED(kAllocateInOldSpaceStubConstant,
+                HeapConstant(isolate()->builtins()->AllocateInOldSpace()));
+}
 
 Node* JSGraph::CEntryStubConstant(int result_size) {
   if (result_size == 1) {
@@ -81,9 +90,6 @@ Node* JSGraph::NaNConstant() {
 
 
 Node* JSGraph::HeapConstant(Handle<HeapObject> value) {
-  if (value->IsConsString()) {
-    value = String::Flatten(Handle<String>::cast(value), TENURED);
-  }
   Node** loc = cache_.FindHeapConstant(value);
   if (*loc == nullptr) {
     *loc = graph()->NewNode(common()->HeapConstant(value));