[turbofan] Introduce LoadFunctionPrototype simplified operator.

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 1176 matching lines @@
             simplified()->StoreField(AccessBuilder::ForMap()), receiver,
             jsgraph()->Constant(transition_map), effect, control);
       }
       effect = graph()->NewNode(simplified()->StoreField(field_access), storage,
                                 value, effect, control);
       if (access_info.HasTransitionMap()) {
         effect = graph()->NewNode(common()->FinishRegion(),
                                   jsgraph()->UndefinedConstant(), effect);
       }
     }
+  } else if (access_info.IsFunctionPrototype()) {
+    DCHECK_EQ(AccessMode::kLoad, access_mode);
+    value = effect = graph()->NewNode(simplified()->LoadFunctionPrototype(),
+                                      receiver, effect, control);
   } else {
     DCHECK(access_info.IsGeneric());
     DCHECK_EQ(AccessMode::kStore, access_mode);
     DCHECK_EQ(FeedbackVectorSlotKind::STORE_IC, vector->GetKind(slot));
     Callable callable =
         CodeFactory::StoreICInOptimizedCode(isolate(), language_mode);
     const CallInterfaceDescriptor& descriptor = callable.descriptor();
     CallDescriptor* desc = Linkage::GetStubCallDescriptor(
         isolate(), graph()->zone(), descriptor,
         descriptor.GetStackParameterCount(), CallDescriptor::kNeedsFrameState,
@@ skipping 596 matching lines @@
   return jsgraph()->javascript();
 }
 
 SimplifiedOperatorBuilder* JSNativeContextSpecialization::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8