Make CTX allocatable by the register allocator.

runtime/vm/isolate.h

 // Copyright (c) 2013, 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_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/base_isolate.h"
@@ skipping 169 matching lines @@
   Heap* heap() const { return heap_; }
   void set_heap(Heap* value) { heap_ = value; }
   static intptr_t heap_offset() { return OFFSET_OF(Isolate, heap_); }
 
   ObjectStore* object_store() const { return object_store_; }
   void set_object_store(ObjectStore* value) { object_store_ = value; }
   static intptr_t object_store_offset() {
     return OFFSET_OF(Isolate, object_store_);
   }
 
-  RawContext* top_context() const { return top_context_; }
-  void set_top_context(RawContext* value) { top_context_ = value; }
-  static intptr_t top_context_offset() {
-    return OFFSET_OF(Isolate, top_context_);
-  }
-
   uword top_exit_frame_info() const { return top_exit_frame_info_; }
   void set_top_exit_frame_info(uword value) { top_exit_frame_info_ = value; }
   static intptr_t top_exit_frame_info_offset() {
     return OFFSET_OF(Isolate, top_exit_frame_info_);
   }
 
   static intptr_t vm_tag_offset() {
     return OFFSET_OF(Isolate, vm_tag_);
   }
 
@@ skipping 427 matching lines @@
   ClassTable class_table_;
   MegamorphicCacheTable megamorphic_cache_table_;
   Dart_MessageNotifyCallback message_notify_callback_;
   char* name_;
   int64_t start_time_;
   Dart_Port main_port_;
   uint64_t pause_capability_;
   uint64_t terminate_capability_;
   Heap* heap_;
   ObjectStore* object_store_;
-  RawContext* top_context_;
   uword top_exit_frame_info_;
   void* init_callback_data_;
   Dart_EnvironmentCallback environment_callback_;
   Dart_LibraryTagHandler library_tag_handler_;
   ApiState* api_state_;
   StubCode* stub_code_;
   Debugger* debugger_;
   bool single_step_;
   bool resume_request_;
   Random random_;
@@ skipping 201 matching lines @@
   char* exception_callback_name_;
   uint8_t* serialized_args_;
   intptr_t serialized_args_len_;
   uint8_t* serialized_message_;
   intptr_t serialized_message_len_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_