Fix old space check in IsSlotInBlackObject.

BUG=

Review URL: https://codereview.chromium.org/993513009

Cr-Commit-Position: refs/heads/master@{#27090}

src/heap/mark-compact.cc

@@ -3059,7 +3059,8 @@ bool MarkCompactCollector::TryPromoteObject(HeapObject* object,
 
 bool MarkCompactCollector::IsSlotInBlackObject(Page* p, Address slot) {
   // This function does not support large objects right now.
-  if (p->owner() == NULL) return true;
+  Space* owner = p->owner();
+  if (owner == heap_->lo_space() || owner == NULL) return true;
 
   uint32_t mark_bit_index = p->AddressToMarkbitIndex(slot);
   unsigned int start_index = mark_bit_index >> Bitmap::kBitsPerCellLog2;