Disable const in strict mode.

test/mjsunit/strict-mode.js

Index: test/mjsunit/strict-mode.js
diff --git a/test/mjsunit/strict-mode.js b/test/mjsunit/strict-mode.js
index ab3e535ec33055a8245ff5280c8b196a74170d3c..28a0455a60a06231b06bdefff4e35d044a2c81b9 100644
--- a/test/mjsunit/strict-mode.js
+++ b/test/mjsunit/strict-mode.js
@@ -280,6 +280,11 @@ CheckStrictMode("function strict() { print(--arguments); }", SyntaxError);
 CheckStrictMode("function strict() { var x = --eval; }", SyntaxError);
 CheckStrictMode("function strict() { var x = --arguments; }", SyntaxError);
 
+// Use of const in strict mode is disallowed in anticipation of ES Harmony.
+CheckStrictMode("const x = 0;", SyntaxError);
+CheckStrictMode("for (const x = 0; false;) {}", SyntaxError);
+CheckStrictMode("function strict() { const x = 0; }", SyntaxError);
+
 // Delete of an unqualified identifier
 CheckStrictMode("delete unqualified;", SyntaxError);
 CheckStrictMode("function strict() { delete unqualified; }", SyntaxError);