[strong] Implement strong mode restrictions on property access

src/runtime/runtime-debug.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/v8.h"
 
 #include "src/accessors.h"
 #include "src/arguments.h"
 #include "src/compiler.h"
 #include "src/debug.h"
@@ skipping 63 matching lines @@
       case LookupIterator::INTEGER_INDEXED_EXOTIC:
       case LookupIterator::INTERCEPTOR:
       case LookupIterator::JSPROXY:
         return it->isolate()->factory()->undefined_value();
       case LookupIterator::ACCESSOR: {
         Handle<Object> accessors = it->GetAccessors();
         if (!accessors->IsAccessorInfo()) {
           return it->isolate()->factory()->undefined_value();
         }
         MaybeHandle<Object> maybe_result =
-            JSObject::GetPropertyWithAccessor(it);
+            JSObject::GetPropertyWithAccessor(it, Strength::WEAK);
         Handle<Object> result;
         if (!maybe_result.ToHandle(&result)) {
           result = handle(it->isolate()->pending_exception(), it->isolate());
           it->isolate()->clear_pending_exception();
           if (has_caught != NULL) *has_caught = true;
         }
         return result;
       }
 
       case LookupIterator::DATA:
@@ skipping 3119 matching lines @@
   return Smi::FromInt(isolate->debug()->is_active());
 }
 
 
 RUNTIME_FUNCTION(Runtime_DebugBreakInOptimizedCode) {
   UNIMPLEMENTED();
   return NULL;
 }
 }  // namespace internal
 }  // namespace v8