Add script context with context-allocated "const this"

test/mjsunit/regress/regress-crbug-498811.js

Index: test/mjsunit/regress/regress-crbug-498811.js
diff --git a/test/message/strict-formal-parameters.js b/test/mjsunit/regress/regress-crbug-498811.js
similarity index 79%
copy from test/message/strict-formal-parameters.js
copy to test/mjsunit/regress/regress-crbug-498811.js
index a6c75317b374e6a06d3497f3812f3f220db3e880..53f57b8c1712da1d6cd42db76d299bfef7389c5f 100644
--- a/test/message/strict-formal-parameters.js
+++ b/test/mjsunit/regress/regress-crbug-498811.js
@@ -2,5 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// NO HARNESS
+
 "use strict";
-function foo(b, a, a, d) { return a }
+let l = 0;
+eval("eval('this')");