Refactor Maps' code_cache

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 631615a50d72333387e15b60f2cd6ed013c52d17..362944a71af701125f84525efc237e1bca2f682e 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -5841,7 +5841,7 @@ class Map: public HeapObject {
                                     LayoutDescriptor* layout_descriptor);
 
   // [stub cache]: contains stubs compiled for this map.
-  DECL_ACCESSORS(code_cache, Object)
+  DECL_ACCESSORS(code_cache, FixedArray)
 
   // [dependent code]: list of optimized codes that weakly embed this map.
   DECL_ACCESSORS(dependent_code, DependentCode)
@@ -8140,9 +8140,6 @@ class CodeCacheHashTable: public HashTable<CodeCacheHashTable,
 
   DECLARE_CAST(CodeCacheHashTable)
 
-  // Initial size of the fixed array backing the hash table.
-  static const int kInitialSize = 16;
-
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCacheHashTable);
 };