Remove isolate pointer from context objects.

runtime/vm/raw_object.h

 // Copyright (c) 2012, 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_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "platform/assert.h"
 #include "vm/atomic.h"
 #include "vm/globals.h"
@@ skipping 1155 matching lines @@
   // Variable length data follows here.
   intptr_t* data() { OPEN_ARRAY_START(intptr_t, intptr_t); }
   const intptr_t* data() const { OPEN_ARRAY_START(intptr_t, intptr_t); }
 };
 
 
 class RawContext : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Context);
 
   int32_t num_variables_;
-  Isolate* isolate_;
 
   RawObject** from() { return reinterpret_cast<RawObject**>(&ptr()->parent_); }
   RawContext* parent_;
 
   // Variable length data follows here.
   RawInstance** data() { OPEN_ARRAY_START(RawInstance*, RawInstance*); }
   RawInstance* const* data() const {
       OPEN_ARRAY_START(RawInstance*, RawInstance*);
   }
   RawObject** to(intptr_t num_vars) {
@@ skipping 882 matching lines @@
   COMPILE_ASSERT(kExternalTypedDataInt8ArrayCid ==
                  kTypedDataInt8ArrayViewCid + 15);
   COMPILE_ASSERT(kByteBufferCid == kExternalTypedDataInt8ArrayCid + 14);
   COMPILE_ASSERT(kNullCid == kByteBufferCid + 1);
   return (kNullCid - kTypedDataInt8ArrayCid);
 }
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_