[serializer] make snapshot reproducible.

src/heap/heap.cc

 // Copyright 2012 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/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/bits.h"
@@ skipping 5374 matching lines @@
   // something that looks like an out of range Smi to the GC.
 
   // Set up the special root array entries containing the stack limits.
   // These are actually addresses, but the tag makes the GC ignore it.
   roots_[kStackLimitRootIndex] = reinterpret_cast<Object*>(
       (isolate_->stack_guard()->jslimit() & ~kSmiTagMask) | kSmiTag);
   roots_[kRealStackLimitRootIndex] = reinterpret_cast<Object*>(
       (isolate_->stack_guard()->real_jslimit() & ~kSmiTagMask) | kSmiTag);
 }
 
+void Heap::ClearStackLimits() {
+  roots_[kStackLimitRootIndex] = Smi::FromInt(0);
+  roots_[kRealStackLimitRootIndex] = Smi::FromInt(0);
+}
 
 void Heap::PrintAlloctionsHash() {
   uint32_t hash = StringHasher::GetHashCore(raw_allocations_hash_);
   PrintF("\n### Allocations = %u, hash = 0x%08x\n", allocations_count(), hash);
 }
 
 
 void Heap::NotifyDeserializationComplete() {
   deserialization_complete_ = true;
 #ifdef DEBUG
@@ skipping 1071 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8