Revert of [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 2b15fe3333aa53b95272531ff6c938d0562530b2..1c5b1824fea5e26b999462172136465a9274ea56 100644
--- a/src/compiler/js-graph.cc
+++ b/src/compiler/js-graph.cc
@@ -81,6 +81,9 @@
 
 
 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));