Revert "Revert "Favor free list allocation to bump pointer allocation.""

runtime/vm/freelist.h

Index: runtime/vm/freelist.h
diff --git a/runtime/vm/freelist.h b/runtime/vm/freelist.h
index 7edc4fea48d724973b16a9cb777623758965f687..4f2a0df0628c76e45f4bc9199c2c98d208f08d19 100644
--- a/runtime/vm/freelist.h
+++ b/runtime/vm/freelist.h
@@ -7,6 +7,7 @@
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
+#include "vm/bit_set.h"
 #include "vm/raw_object.h"
 
 namespace dart {
@@ -78,6 +79,10 @@ class FreeList {
 
   void Reset();
 
+  intptr_t Length(int index) const;
+
+  void Print() const;
+
  private:
   static const int kNumLists = 128;
 
@@ -88,6 +93,8 @@ class FreeList {
 
   void SplitElementAfterAndEnqueue(FreeListElement* element, intptr_t size);
 
+  BitSet<kNumLists + 1> free_map_;
+
   FreeListElement* free_lists_[kNumLists + 1];
 
   DISALLOW_COPY_AND_ASSIGN(FreeList);