Object pool with support for untagged entries.

runtime/vm/assembler_mips.h

Index: runtime/vm/assembler_mips.h
diff --git a/runtime/vm/assembler_mips.h b/runtime/vm/assembler_mips.h
index 0ccfb86e0787d692b4b17f67f3186c6068daa2a2..9f8a4db61aa8339ead955eb7b8067aa4940922ea 100644
--- a/runtime/vm/assembler_mips.h
+++ b/runtime/vm/assembler_mips.h
@@ -263,11 +263,11 @@ class Assembler : public ValueObject {
     return buffer_.pointer_offsets();
   }
 
-  const GrowableObjectArray& object_pool_data() const {
-    return object_pool_.data();
-  }
+  ObjectPoolWrapper& object_pool_wrapper() { return object_pool_wrapper_; }
 
-  ObjectPool& object_pool() { return object_pool_; }
+  RawObjectPool* MakeObjectPool() {
+    return object_pool_wrapper_.MakeObjectPool();
+  }
 
   void FinalizeInstructions(const MemoryRegion& region) {
     buffer_.FinalizeInstructions(region);
@@ -928,8 +928,8 @@ class Assembler : public ValueObject {
 
   void BranchLinkPatchable(const ExternalLabel* label) {
     ASSERT(!in_delay_slot_);
-    const int32_t offset = Array::element_offset(
-        object_pool_.FindExternalLabel(label, kPatchable));
+    const int32_t offset = ObjectPool::element_offset(
+        object_pool_wrapper_.FindExternalLabel(label, kPatchable));
     LoadWordFromPoolOffset(T9, offset - kHeapObjectTag);
     jalr(T9);
     delay_slot_available_ = false;  // CodePatcher expects a nop.
@@ -1614,7 +1614,7 @@ class Assembler : public ValueObject {
 
  private:
   AssemblerBuffer buffer_;
-  ObjectPool object_pool_;  // Objects and patchable jump targets.
+  ObjectPoolWrapper object_pool_wrapper_;
 
   intptr_t prologue_offset_;