Fixes bug in far branches on MIPS.

runtime/vm/assembler_mips.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_ASSEMBLER_MIPS_H_
 #define VM_ASSEMBLER_MIPS_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_mips.h directly; use assembler.h instead.
 #endif
@@ skipping 157 matching lines @@
   }
   const GrowableObjectArray& object_pool() const { return object_pool_; }
   void FinalizeInstructions(const MemoryRegion& region) {
     buffer_.FinalizeInstructions(region);
   }
 
   bool use_far_branches() const {
     return FLAG_use_far_branches || use_far_branches_;
   }
 
+  void set_use_far_branches(bool b) {
+    ASSERT(buffer_.Size() == 0);
+    use_far_branches_ = b;
+  }
+
   void EnterFrame();
   void LeaveFrameAndReturn();
 
   // Set up a stub frame so that the stack traversal code can easily identify
   // a stub frame.
   void EnterStubFrame(bool load_pp = false);
   void LeaveStubFrame();
   // A separate macro for when a Ret immediately follows, so that we can use
   // the branch delay slot.
   void LeaveStubFrameAndReturn(Register ra = RA);
@@ skipping 968 matching lines @@
   // On some other platforms, we draw a distinction between safe and unsafe
   // smis.
   static bool IsSafe(const Object& object) { return true; }
   static bool IsSafeSmi(const Object& object) { return object.IsSmi(); }
 
  private:
   AssemblerBuffer buffer_;
   GrowableObjectArray& object_pool_;  // Objects and patchable jump targets.
   intptr_t prologue_offset_;
 
-  const bool use_far_branches_;
+  bool use_far_branches_;
   bool delay_slot_available_;
   bool in_delay_slot_;
 
   int32_t AddObject(const Object& obj);
   int32_t AddExternalLabel(const ExternalLabel* label);
 
   class CodeComment : public ZoneAllocated {
    public:
     CodeComment(intptr_t pc_offset, const String& comment)
         : pc_offset_(pc_offset), comment_(comment) { }
@@ skipping 109 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_MIPS_H_