Supports FrameLookup vm test 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 {
 
+// The constant kExitLinkOffsetInEntryFrame must be kept in sync with the
+// code in the InvokeDartCode stub.
+static const int kExitLinkOffsetInEntryFrame = -10 * kWordSize;
 static const int kPcAddressOffsetFromSp = -2 * kWordSize;
 static const int kEntrypointMarkerOffsetFromFp = 2 * kWordSize;
 static const int kSpOffsetFromPreviousFp = 3 * kWordSize;
 
 
 intptr_t StackFrame::PcAddressOffsetFromSp() {
   return kPcAddressOffsetFromSp;
 }
 
 
@@ skipping 25 matching lines @@
 
 
 void StackFrameIterator::SetupLastExitFrameData() {
   Isolate* current = Isolate::Current();
   uword exit_marker = current->top_exit_frame_info();
   frames_.fp_ = exit_marker;
 }
 
 
 void StackFrameIterator::SetupNextExitFrameData() {
-  UNIMPLEMENTED();
+  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