Reapply "Move megamorphic cache table into the Dart heap."

runtime/vm/megamorphic_cache_table.h

Index: runtime/vm/megamorphic_cache_table.h
diff --git a/runtime/vm/megamorphic_cache_table.h b/runtime/vm/megamorphic_cache_table.h
index eafb35b12b6ed45d8f656c62668d1518adad1f10..c47d4d89f6e9a89da1b20d7913c339d54d67850f 100644
--- a/runtime/vm/megamorphic_cache_table.h
+++ b/runtime/vm/megamorphic_cache_table.h
@@ -11,6 +11,7 @@ namespace dart {
 
 class Array;
 class Function;
+class Isolate;
 class ObjectPointerVisitor;
 class RawArray;
 class RawFunction;
@@ -19,36 +20,24 @@ class RawMegamorphicCache;
 class RawString;
 class String;
 
-class MegamorphicCacheTable {
+class MegamorphicCacheTable : public AllStatic {
  public:
-  MegamorphicCacheTable();
-  ~MegamorphicCacheTable();
+  static RawFunction* miss_handler(Isolate* isolate);
+  static void InitMissHandler(Isolate* isolate);
 
-  RawFunction* miss_handler() const { return miss_handler_function_; }
-  void InitMissHandler();
+  static RawMegamorphicCache* Lookup(Isolate* isolate,
+                                     const String& name,
+                                     const Array& descriptor);
 
-  RawMegamorphicCache* Lookup(const String& name, const Array& descriptor);
-
-  void VisitObjectPointers(ObjectPointerVisitor* visitor);
-
-  void PrintSizes();
+  static void PrintSizes(Isolate* isolate);
 
  private:
-  struct Entry {
-    RawString* name;
-    RawArray* descriptor;
-    RawMegamorphicCache* cache;
+  enum {
+    kEntryNameOffset = 0,
+    kEntryDescriptorOffset,
+    kEntryCacheOffset,
+    kEntrySize
   };
-
-  static const int kCapacityIncrement = 128;
-
-  RawFunction* miss_handler_function_;
-  RawCode* miss_handler_code_;
-  intptr_t capacity_;
-  intptr_t length_;
-  Entry* table_;
-
-  DISALLOW_COPY_AND_ASSIGN(MegamorphicCacheTable);
 };
 
 }  // namespace dart