[runtime] Throw if attempting to re-declaring an accessor.

src/runtime/runtime-scopes.cc

 // Copyright 2014 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/runtime/runtime-utils.h"
 
 #include <memory>
 
 #include "src/accessors.h"
 #include "src/arguments.h"
@@ skipping 70 matching lines @@
     DCHECK(is_function_declaration);
     if ((old_attributes & DONT_DELETE) != 0) {
       // Only allow reconfiguring globals to functions in user code (no
       // natives, which are marked as read-only).
       DCHECK((attr & READ_ONLY) == 0);
 
       // Check whether we can reconfigure the existing property into a
       // function.
       PropertyDetails old_details = it.property_details();
       if (old_details.IsReadOnly() || old_details.IsDontEnum() ||
-          (it.state() == LookupIterator::ACCESSOR &&
-           it.GetAccessors()->IsAccessorPair())) {
+          (it.state() == LookupIterator::ACCESSOR)) {
         // ECMA-262 section 15.1.11 GlobalDeclarationInstantiation 5.d:
         // If hasRestrictedGlobal is true, throw a SyntaxError exception.
         // ECMA-262 section 18.2.1.3 EvalDeclarationInstantiation 8.a.iv.1.b:
         // If fnDefinable is false, throw a TypeError exception.
         return ThrowRedeclarationError(isolate, name, redeclaration_type);
       }
       // If the existing property is not configurable, keep its attributes. Do
       attr = old_attributes;
     }
 
@@ skipping 871 matching lines @@
 RUNTIME_FUNCTION(Runtime_StoreLookupSlot_Strict) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
   CONVERT_ARG_HANDLE_CHECKED(String, name, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, value, 1);
   RETURN_RESULT_OR_FAILURE(isolate, StoreLookupSlot(name, value, STRICT));
 }
 
 }  // namespace internal
 }  // namespace v8