[turbofan] Fix various issues with --turbo-inlining enabled.

src/compiler/js-type-feedback-lowering.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/js-type-feedback-lowering.h"
 
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-properties.h"
 #include "src/objects-inl.h"  // TODO(mstarzinger): Temporary cycle breaker!
@@ skipping 25 matching lines @@
 Reduction JSTypeFeedbackLowering::ReduceJSLoadNamed(Node* node) {
   DCHECK_EQ(IrOpcode::kJSLoadNamed, node->opcode());
   Node* receiver = NodeProperties::GetValueInput(node, 0);
   Type* receiver_type = NodeProperties::GetType(receiver);
   Node* frame_state = NodeProperties::GetFrameStateInput(node, 1);
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
   // We need to make optimistic assumptions to continue.
   if (!(flags() & kDeoptimizationEnabled)) return NoChange();
   LoadNamedParameters const& p = LoadNamedParametersOf(node->op());
-  if (p.feedback().vector().is_null()) return NoChange();
+  if (!p.feedback().IsValid()) return NoChange();  // No feedback.
   if (p.name().is_identical_to(factory()->length_string())) {
     LoadICNexus nexus(p.feedback().vector(), p.feedback().slot());
     MapHandleList maps;
     if (nexus.ExtractMaps(&maps) > 0) {
       for (Handle<Map> map : maps) {
         if (map->instance_type() >= FIRST_NONSTRING_TYPE) return NoChange();
       }
       // Optimistic optimization for "length" property of strings.
       if (receiver_type->Maybe(Type::TaggedSigned())) {
         Node* check = graph()->NewNode(simplified()->ObjectIsSmi(), receiver);
@@ skipping 53 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSTypeFeedbackLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8