Fix compilation when disabling debugger support.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index dd1f710b25224a9521636d12cb221871a39e4f59..e9925c209f46f8a1e057155405328d0ec141487d 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -1392,15 +1392,15 @@ class Heap {
     STRONG_ROOT_LIST(ROOT_INDEX_DECLARATION)
 #undef ROOT_INDEX_DECLARATION
 
-// Utility type maps
-#define DECLARE_STRUCT_MAP(NAME, Name, name) k##Name##MapRootIndex,
-  STRUCT_LIST(DECLARE_STRUCT_MAP)
-#undef DECLARE_STRUCT_MAP
-
 #define SYMBOL_INDEX_DECLARATION(name, str) k##name##RootIndex,
     SYMBOL_LIST(SYMBOL_INDEX_DECLARATION)
 #undef SYMBOL_DECLARATION
 
+    // Utility type maps
+#define DECLARE_STRUCT_MAP(NAME, Name, name) k##Name##MapRootIndex,
+    STRUCT_LIST(DECLARE_STRUCT_MAP)
+#undef DECLARE_STRUCT_MAP
+
     kSymbolTableRootIndex,
     kStrongRootListLength = kSymbolTableRootIndex,
     kRootListLength