Eliminate object table and use regular object pool for deoptimization infos.

runtime/vm/assembler_x64.h

Index: runtime/vm/assembler_x64.h
===================================================================
--- runtime/vm/assembler_x64.h	(revision 45086)
+++ runtime/vm/assembler_x64.h	(working copy)
@@ -897,8 +897,12 @@
   const ZoneGrowableArray<intptr_t>& GetPointerOffsets() const {
     return buffer_.pointer_offsets();
   }
-  const GrowableObjectArray& object_pool() const { return object_pool_.data(); }
+  const GrowableObjectArray& object_pool_data() const {
+    return object_pool_.data();
+  }
 
+  ObjectPool& object_pool() { return object_pool_; }
+
   void FinalizeInstructions(const MemoryRegion& region) {
     buffer_.FinalizeInstructions(region);
   }