Implement Harmony sets and maps.

src/macros.py

Index: src/macros.py
diff --git a/src/macros.py b/src/macros.py
index a42e83c60206dc9519ca17fec061e71704a80ad4..7d41d084408ebe5e5d89032c81c4bfc47273092d 100644
--- a/src/macros.py
+++ b/src/macros.py
@@ -193,6 +193,12 @@ const WRITABLE_INDEX = 4;
 const ENUMERABLE_INDEX = 5;
 const CONFIGURABLE_INDEX = 6;
 
+# For collection.js, operation types for SetAccess.
+# Matches SetAccessOperation from runtime.cc
+const SET_ACCESS_ADD = 0;
+const SET_ACCESS_HAS = 1;
+const SET_ACCESS_DELETE = 2;
+
 # For messages.js
 # Matches Script::Type from objects.h
 const TYPE_NATIVE = 0;