Enables stack frame vm tests on MIPS.

runtime/vm/stack_frame_mips.cc

 // 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.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/stack_frame.h"
 
 namespace dart {
@@ skipping 20 matching lines @@
   return *(reinterpret_cast<uword*>(fp()));
 }
 
 
 uword StackFrame::GetCallerSp() const {
   return fp() + kSpOffsetFromPreviousFp;
 }
 
 
 intptr_t EntryFrame::ExitLinkOffset() const {
-  UNIMPLEMENTED();
-  return 0;
+  return kExitLinkOffsetInEntryFrame;
 }
 
 
 intptr_t EntryFrame::SavedContextOffset() const {
   UNIMPLEMENTED();
   return 0;
 }
 
 
 void StackFrameIterator::SetupLastExitFrameData() {
   Isolate* current = Isolate::Current();
   uword exit_marker = current->top_exit_frame_info();
   frames_.fp_ = exit_marker;
 }
 
 
 void StackFrameIterator::SetupNextExitFrameData() {
   uword exit_address = entry_.fp() + kExitLinkOffsetInEntryFrame;
   uword exit_marker = *reinterpret_cast<uword*>(exit_address);
   frames_.fp_ = exit_marker;
   frames_.sp_ = 0;
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS