Parsing of basic module declarations (no imports/exports yet).

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 32bf7a84b6f49124b29083654b75bb83884bae1e..4aba9136e72694905af1d931d042b3522565cf04 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -130,6 +130,7 @@ namespace internal {
   V(Map, catch_context_map, CatchContextMap)                                   \
   V(Map, with_context_map, WithContextMap)                                     \
   V(Map, block_context_map, BlockContextMap)                                   \
+  V(Map, module_context_map, ModuleContextMap)                                 \
   V(Map, oddball_map, OddballMap)                                              \
   V(Map, message_object_map, JSMessageObjectMap)                               \
   V(Map, foreign_map, ForeignMap)                                              \