Intrinsify UserTag operations on all architectures

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 "platform/thread.h"
@@ skipping 460 matching lines @@
 
   void ProfileInterrupt();
 
   VMTagCounters* vm_tag_counters() {
     return &vm_tag_counters_;
   }
 
   uword user_tag() const {
     return user_tag_;
   }
+  static intptr_t user_tag_offset() {
+    return OFFSET_OF(Isolate, user_tag_);
+  }
+  static intptr_t current_tag_offset() {
+    return OFFSET_OF(Isolate, current_tag_);
+  }
 
   RawGrowableObjectArray* tag_table() const { return tag_table_; }
   void set_tag_table(const GrowableObjectArray& value);
 
   RawUserTag* current_tag() const { return current_tag_; }
   void set_current_tag(const UserTag& tag);
   void clear_current_tag();
 
 #if defined(DEBUG)
 #define REUSABLE_HANDLE_SCOPE_ACCESSORS(object)                                \
@@ skipping 221 matching lines @@
   char* script_url_;
   char* library_url_;
   char* class_name_;
   char* function_name_;
   char* exception_callback_name_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_