Expose a lower bound of malloc'd memory via heap statistics

src/objects.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/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 8629 matching lines @@
     }
   }
   accumulator->NextPrototype();  // Prepare for accumulating keys.
   // 15. If extensibleTarget is true and targetNonconfigurableKeys is empty,
   //     then:
   if (extensible_target && nonconfigurable_keys_length == 0) {
     // 15a. Return trapResult.
     return accumulator->AddKeysFromProxy(proxy, trap_result);
   }
   // 16. Let uncheckedResultKeys be a new List which is a copy of trapResult.
-  Zone set_zone;
+  Zone set_zone(isolate->allocator());
   const int kPresent = 1;
   const int kGone = 0;
   IdentityMap<int> unchecked_result_keys(isolate->heap(), &set_zone);
   int unchecked_result_keys_size = 0;
   for (int i = 0; i < trap_result->length(); ++i) {
     DCHECK(trap_result->get(i)->IsUniqueName());
     Object* key = trap_result->get(i);
     int* entry = unchecked_result_keys.Get(key);
     if (*entry != kPresent) {
       *entry = kPresent;
@@ skipping 11093 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8