Turn LoadIndexedInterceptor into a Turbofan stub

src/compiler/code-stub-assembler.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/code-stub-assembler.h"
 
 #include <ostream>
 
 #include "src/code-factory.h"
 #include "src/compiler/graph.h"
@@ skipping 203 matching lines @@
 #define DEFINE_CODE_STUB_ASSEMBER_UNARY_OP(name) \
   Node* CodeStubAssembler::name(Node* a) { return raw_assembler_->name(a); }
 CODE_STUB_ASSEMBLER_UNARY_OP_LIST(DEFINE_CODE_STUB_ASSEMBER_UNARY_OP)
 #undef DEFINE_CODE_STUB_ASSEMBER_UNARY_OP
 
 Node* CodeStubAssembler::WordIsSmi(Node* a) {
   return WordEqual(raw_assembler_->WordAnd(a, IntPtrConstant(kSmiTagMask)),
                    IntPtrConstant(0));
 }
 
+Node* CodeStubAssembler::WordIsPositiveSmi(Node* a) {
+  return WordEqual(
+      raw_assembler_->WordAnd(a, IntPtrConstant(kSmiTagMask | kSmiSignMask)),
+      IntPtrConstant(0));
+}
+
 Node* CodeStubAssembler::LoadBufferObject(Node* buffer, int offset,
                                           MachineType rep) {
   return raw_assembler_->Load(rep, buffer, IntPtrConstant(offset));
 }
 
 Node* CodeStubAssembler::LoadObjectField(Node* object, int offset,
                                          MachineType rep) {
   return raw_assembler_->Load(rep, object,
                               IntPtrConstant(offset - kHeapObjectTag));
 }
@@ skipping 641 matching lines @@
       }
     }
   }
 
   bound_ = true;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8