Fix d8 build error on a fresh checkout.

Review URL: http://codereview.chromium.org/2809069

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5118 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

tools/js2c.py

@@ -275,8 +275,8 @@ def JS2C(source, target, env):
   debugger_ids = []
   modules = []
   # Locate the macros file name.
-  consts = {}
-  macros = {}
+  consts = []
+  macros = []
   for s in source:
     if 'macros.py' == (os.path.split(str(s))[1]):
       (consts, macros) = ReadMacros(ReadLines(str(s)))