Towards removing dependency from generic lowering on compilation info.

src/compiler/js-context-specialization.cc

Index: src/compiler/js-context-specialization.cc
diff --git a/src/compiler/js-context-specialization.cc b/src/compiler/js-context-specialization.cc
index bdf142763a8887ca3db22cdda719b94eae24f86a..70911915122d1274bc705c739d025b4e3c4cb286 100644
--- a/src/compiler/js-context-specialization.cc
+++ b/src/compiler/js-context-specialization.cc
@@ -69,6 +69,7 @@ class ContextSpecializationVisitor : public NullNodeVisitor {
 
 void JSContextSpecializer::SpecializeToContext() {
   ReplaceEffectfulWithValue(context_, jsgraph_->Constant(info_->context()));
+  specialized_ = true;
 
   ContextSpecializationVisitor visitor(this);
   jsgraph_->graph()->VisitNodeInputsFromEnd(&visitor);
@@ -152,6 +153,28 @@ Reduction JSContextSpecializer::ReduceJSStoreContext(Node* node) {
 
   return Reducer::Changed(node);
 }
+
+
+Node* JSContextSpecializer::InsertBuiltinLoadBefore(Node* before,
+                                                    Builtins::JavaScript id) {
+  if (specialized_) {
+    Handle<JSFunction> function(
+        JSFunction::cast(info_->context()->builtins()->javascript_builtin(id)));
+    return jsgraph_->HeapConstant(function);
+  }
+  Node* context = NodeProperties::GetContextInput(before);
+  Node* global = jsgraph_->LoadObjectField(
+      context,
+      Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX) + kHeapObjectTag,
+      context, NodeProperties::GetEffectInput(before));
+  Node* builtins = jsgraph_->LoadObjectField(
+      global, JSGlobalObject::kBuiltinsOffset, context, global);
+  Node* function_node = jsgraph_->LoadObjectField(
+      builtins, JSBuiltinsObject::OffsetOfFunctionWithId(id), context,
+      builtins);
+  NodeProperties::ReplaceEffectInput(before, function_node);
+  return function_node;
+}
 }
 }
 }  // namespace v8::internal::compiler