Make CTX allocatable by the register allocator.

runtime/vm/stack_frame.h

 // Copyright (c) 2011, 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_STACK_FRAME_H_
 #define VM_STACK_FRAME_H_
 
 #include "vm/allocation.h"
 #include "vm/object.h"
 #include "vm/stub_code.h"
@@ skipping 132 matching lines @@
 // dart code.
 class EntryFrame : public StackFrame {
  public:
   bool IsValid() const {
     return StubCode::InInvocationStubForIsolate(isolate(), pc());
   }
   bool IsDartFrame(bool validate = true) const { return false; }
   bool IsStubFrame() const { return false; }
   bool IsEntryFrame() const { return true; }
 
-  RawContext* SavedContext() const;
-
   // Visit objects in the frame.
   virtual void VisitObjectPointers(ObjectPointerVisitor* visitor);
 
  protected:
   virtual const char* GetName() const { return "entry"; }
 
  private:
   explicit EntryFrame(Isolate* isolate) : StackFrame(isolate) { }
 
   friend class StackFrameIterator;
@@ skipping 161 matching lines @@
   uword pc_;
   GrowableArray<DeoptInstr*> deopt_instructions_;
   Array& object_table_;
 
   DISALLOW_COPY_AND_ASSIGN(InlinedFunctionsIterator);
 };
 
 }  // namespace dart
 
 #endif  // VM_STACK_FRAME_H_