Distinguish slow from fast sloppy arguments

src/x64/code-stubs-x64.cc

 // Copyright 2013 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/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 656 matching lines @@
   Label has_mapped_parameters, instantiate;
   __ movp(rdi, Operand(rsi, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
   __ movp(rdi, FieldOperand(rdi, GlobalObject::kNativeContextOffset));
   __ testp(rbx, rbx);
   __ j(not_zero, &has_mapped_parameters, Label::kNear);
 
   const int kIndex = Context::SLOPPY_ARGUMENTS_MAP_INDEX;
   __ movp(rdi, Operand(rdi, Context::SlotOffset(kIndex)));
   __ jmp(&instantiate, Label::kNear);
 
-  const int kAliasedIndex = Context::ALIASED_ARGUMENTS_MAP_INDEX;
+  const int kAliasedIndex = Context::FAST_ALIASED_ARGUMENTS_MAP_INDEX;
   __ bind(&has_mapped_parameters);
   __ movp(rdi, Operand(rdi, Context::SlotOffset(kAliasedIndex)));
   __ bind(&instantiate);
 
   // rax = address of new object (tagged)
   // rbx = mapped parameter count (untagged)
   // rcx = argument count (untagged)
   // rdi = address of arguments map (tagged)
   __ movp(FieldOperand(rax, JSObject::kMapOffset), rdi);
   __ LoadRoot(kScratchRegister, Heap::kEmptyFixedArrayRootIndex);
@@ skipping 4735 matching lines @@
                            kStackSpace, nullptr, return_value_operand, NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64