Do deferred migration of maps after deoptimizing once.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 352edaaa669f7c5325c5f9ae19df4091575d9389..70472d16a93311e3c3c7bf40f28d5f291098a94e 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -5712,6 +5712,10 @@ class Map: public HeapObject {
   class IsFrozen:                   public BitField<bool, 26,  1> {};
   class IsUnstable:                 public BitField<bool, 27,  1> {};
   class IsMigrationTarget:          public BitField<bool, 28,  1> {};
+  class HasMigrated:                public BitField<int,  29,  1> {};
+
+  inline void set_has_migrated(bool value);
+  inline bool has_migrated();
 
   // Tells whether the object in the prototype property will be used
   // for instances created from this function.  If the prototype