[turbofan] Remove remaining uses of Class type from the compiler.

src/compiler/js-native-context-specialization.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-native-context-specialization.h"
 
 #include "src/accessors.h"
 #include "src/code-factory.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
@@ skipping 888 matching lines @@
       if (rep == MachineRepresentation::kFloat64) {
         if (!field_index.is_inobject() || field_index.is_hidden_field() ||
             !FLAG_unbox_double_fields) {
           storage = effect = graph()->NewNode(
               simplified()->LoadField(field_access), storage, effect, control);
           field_access.offset = HeapNumber::kValueOffset;
           field_access.name = MaybeHandle<Name>();
         }
         field_access.machine_type = MachineType::Float64();
       }
+      // TODO(turbofan): Track the field_map (if any) on the {field_access} and
+      // use it in LoadElimination to eliminate map checks.
       value = effect = graph()->NewNode(simplified()->LoadField(field_access),
                                         storage, effect, control);
     } else {
       DCHECK_EQ(AccessMode::kStore, access_mode);
       if (rep == MachineRepresentation::kFloat64) {
         value = effect = graph()->NewNode(simplified()->CheckNumber(), value,
                                           effect, control);
 
         if (!field_index.is_inobject() || field_index.is_hidden_field() ||
             !FLAG_unbox_double_fields) {
@@ skipping 30 matching lines @@
           // Unboxed double field, we store directly to the field.
           field_access.machine_type = MachineType::Float64();
         }
       } else if (rep == MachineRepresentation::kTaggedSigned) {
         value = effect = graph()->NewNode(simplified()->CheckTaggedSigned(),
                                           value, effect, control);
       } else if (rep == MachineRepresentation::kTaggedPointer) {
         // Ensure that {value} is a HeapObject.
         value = effect = graph()->NewNode(simplified()->CheckTaggedPointer(),
                                           value, effect, control);
-        if (field_type->NumClasses() == 1) {
+        Handle<Map> field_map;
+        if (access_info.field_map().ToHandle(&field_map)) {
           // Emit a map check for the value.
-          Node* field_map =
-              jsgraph()->Constant(field_type->Classes().Current());
           effect = graph()->NewNode(simplified()->CheckMaps(1), value,
-                                    field_map, effect, control);
-        } else {
-          DCHECK_EQ(0, field_type->NumClasses());
+                                    jsgraph()->HeapConstant(field_map), effect,
+                                    control);
         }
       } else {
         // DCHECK(field_type->Is(Type::Tagged()));
         DCHECK(rep == MachineRepresentation::kTagged);
       }
       Handle<Map> transition_map;
       if (access_info.transition_map().ToHandle(&transition_map)) {
         effect = graph()->NewNode(
             common()->BeginRegion(RegionObservability::kObservable), effect);
         effect = graph()->NewNode(
@@ skipping 504 matching lines @@
 }
 
 
 SimplifiedOperatorBuilder* JSNativeContextSpecialization::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8