Revert "Merge old data and pointer space."

src/heap/store-buffer-inl.h

Index: src/heap/store-buffer-inl.h
diff --git a/src/heap/store-buffer-inl.h b/src/heap/store-buffer-inl.h
index 806680e145d43ac066d6d92e59a757d4ff957c0c..ccbe339534ddd97fcaba71312570a825d1dce84d 100644
--- a/src/heap/store-buffer-inl.h
+++ b/src/heap/store-buffer-inl.h
@@ -18,6 +18,7 @@ Address StoreBuffer::TopAddress() {
 void StoreBuffer::Mark(Address addr) {
   DCHECK(!heap_->cell_space()->Contains(addr));
   DCHECK(!heap_->code_space()->Contains(addr));
+  DCHECK(!heap_->old_data_space()->Contains(addr));
   Address* top = reinterpret_cast<Address*>(heap_->store_buffer_top());
   *top++ = addr;
   heap_->public_set_store_buffer_top(top);
@@ -34,6 +35,7 @@ void StoreBuffer::EnterDirectlyIntoStoreBuffer(Address addr) {
   if (store_buffer_rebuilding_enabled_) {
     SLOW_DCHECK(!heap_->cell_space()->Contains(addr) &&
                 !heap_->code_space()->Contains(addr) &&
+                !heap_->old_data_space()->Contains(addr) &&
                 !heap_->new_space()->Contains(addr));
     Address* top = old_top_;
     *top++ = addr;