Add a second kind of HandleScope that ties the lifetime of Handles created in its scope to the life…

src/handles.cc

Index: src/handles.cc
diff --git a/src/handles.cc b/src/handles.cc
index def1604ac7438c5769a0cb6287fd009dee54758d..39bb95c40b9bd8e79cdd8306d26b4ff0b3a37918 100644
--- a/src/handles.cc
+++ b/src/handles.cc
@@ -958,4 +958,42 @@ int Utf8Length(Handle<String> str) {
   return len;
 }
 
+
+GatheringHandleScope::GatheringHandleScope(CompilationInfo* info)
+    : info_(info) {
+  Isolate* isolate = info->isolate();
+  v8::ImplementationUtilities::HandleScopeData* current =
+      isolate->handle_scope_data();
+  prev_next_ = current->next;
+  prev_limit_ = current->limit;
+
+  HandleScopeImplementer* impl = isolate->handle_scope_implementer();
+  impl->set_last_block_before_compilation();
+  Object** new_next = impl->GetSpareOrNewBlock();
+  Object** new_limit = &new_next[kHandleBlockSize];
+  impl->blocks()->Add(new_next);
+
+  current->next = new_next;
+  current->limit = new_limit;
+  current->level++;
+}
+
+
+GatheringHandleScope::~GatheringHandleScope() {
+  Isolate* isolate = info_->isolate();
+  HandleScopeImplementer* impl = isolate->handle_scope_implementer();
+  HandleScopeImplementer::HiddenExtensions* extensions =
+      impl->HideExtensions(prev_limit_);
+  info_->RememberHiddenExtensions(extensions);
+
+  v8::ImplementationUtilities::HandleScopeData* current =
+      isolate->handle_scope_data();
+  current->next = prev_next_;
+  current->limit = prev_limit_;
+
+  impl->unset_last_block_before_compilation();
+  current->level--;
+}
+
+
 } }  // namespace v8::internal