Fix exception for assignment to uninitialised const

src/messages.js

Index: src/messages.js
diff --git a/src/messages.js b/src/messages.js
index 37182414ec11802a939030e7cfe75f1a5e1d8df2..ba739987897417c7917901659d68f892cc8fe0ac 100644
--- a/src/messages.js
+++ b/src/messages.js
@@ -174,7 +174,7 @@ var kMessages = {
   generator_poison_pill:         ["'caller' and 'arguments' properties may not be accessed on generator functions."],
   cant_prevent_ext_external_array_elements: ["Cannot prevent extension of an object with external array elements"],
   redef_external_array_element:  ["Cannot redefine a property of an object with external array elements"],
-  harmony_const_assign:          ["Assignment to constant variable."],
+  const_assign:                  ["Assignment to constant variable."],
   symbol_to_string:              ["Cannot convert a Symbol value to a string"],
   symbol_to_primitive:           ["Cannot convert a Symbol wrapper object to a primitive value"],
   symbol_to_number:              ["Cannot convert a Symbol value to a number"],