Rework how enums are implemented and reloaded

runtime/vm/isolate_reload.h

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ISOLATE_RELOAD_H_
 #define VM_ISOLATE_RELOAD_H_
 
 #include "vm/globals.h"
 #include "vm/growable_array.h"
 #include "vm/log.h"
 
 DECLARE_FLAG(bool, trace_reload);
+DECLARE_FLAG(bool, trace_reload_verbose);
 
 // 'Trace Isolate Reload' TIR_Print
 #if defined(_MSC_VER)
 #define TIR_Print(format, ...) \
     if (FLAG_trace_reload) Log::Current()->Print(format, __VA_ARGS__)
 #else
 #define TIR_Print(format, ...) \
     if (FLAG_trace_reload) Log::Current()->Print(format, ##__VA_ARGS__)
 #endif
 
+// 'Verbose Trace Isolate Reload' VTIR_Print
+#if defined(_MSC_VER)
+#define VTIR_Print(format, ...) \
+    if (FLAG_trace_reload_verbose) Log::Current()->Print(format, __VA_ARGS__)
+#else
+#define VTIR_Print(format, ...) \
+    if (FLAG_trace_reload_verbose) Log::Current()->Print(format, ##__VA_ARGS__)
+#endif
+
 namespace dart {
 
 class GrowableObjectArray;
 class Isolate;
 class Library;
 class RawError;
 class RawGrowableObjectArray;
 class RawLibrary;
 class RawObject;
 class RawString;
@@ skipping 105 matching lines @@
   void BuildLibraryMapping();
 
   void AddClassMapping(const Class& replacement_or_new,
                        const Class& original);
 
   void AddLibraryMapping(const Library& replacement_or_new,
                          const Library& original);
 
   void AddStaticFieldMapping(const Field& old_field, const Field& new_field);
 
-  void AddBecomeMapping(const Object& old, const Object& nue);
+  void AddBecomeMapping(const Object& old, const Object& neu);
+  void AddEnumBecomeMapping(const Object& old, const Object& neu);
 
   void RebuildDirectSubclasses();
 
   RawClass* MappedClass(const Class& replacement_or_new);
   RawLibrary* MappedLibrary(const Library& replacement_or_new);
 
   RawObject** from() { return reinterpret_cast<RawObject**>(&script_uri_); }
   RawString* script_uri_;
   RawError* error_;
   RawArray* old_classes_set_storage_;
   RawArray* class_map_storage_;
   RawArray* old_libraries_set_storage_;
   RawArray* library_map_storage_;
   RawArray* become_map_storage_;
+  RawGrowableObjectArray* become_enum_mappings_;
   RawLibrary* saved_root_library_;
   RawGrowableObjectArray* saved_libraries_;
   RawObject** to() { return reinterpret_cast<RawObject**>(&saved_libraries_); }
 
   friend class Isolate;
-  friend class Class;  // AddStaticFieldMapping.
+  friend class Class;  // AddStaticFieldMapping, AddEnumBecomeMapping.
 };
 
 }  // namespace dart
 
 #endif   // VM_ISOLATE_RELOAD_H_