[heap] Eagerly unlink empty kHuge category from free list

Avoid repeatedly traversing empty kHuge empty free list categories. This is an
oversight as all other categories are already eagerly unlinked upon getting
empty (in FreeList::FindNodeIn).

R=ulan@chromium.org

Review-Url: https://codereview.chromium.org/2109473004
Cr-Commit-Position: refs/heads/master@{#37391}

src/heap/spaces.cc

@@ -2387,6 +2387,9 @@ FreeSpace* FreeList::SearchForNodeInList(FreeListCategoryType type,
       DCHECK(IsVeryLong() || Available() == SumFreeLists());
       return node;
     }
+    if (current->is_empty()) {
+      RemoveCategory(current);
+    }
   }
   return node;
 }