[debugger] allow debug-evaluate to change stack and context values.

src/contexts-inl.h

Index: src/contexts-inl.h
diff --git a/src/contexts-inl.h b/src/contexts-inl.h
index c26ce5bd47638d96effeb66180b4b95b656b51ed..344d5db5784cae76ea9c857ee38fa7103231867b 100644
--- a/src/contexts-inl.h
+++ b/src/contexts-inl.h
@@ -105,6 +105,10 @@ bool Context::IsWithContext() {
   return map == map->GetHeap()->with_context_map();
 }
 
+bool Context::IsDebugEvaluateContext() {
+  Map* map = this->map();
+  return map == map->GetHeap()->debug_evaluate_context_map();
+}
 
 bool Context::IsBlockContext() {
   Map* map = this->map();