Simplify implementation of assignment-to-const checks

test/mjsunit/regress/regress-2243.js

Index: test/mjsunit/regress/regress-2243.js
diff --git a/test/mjsunit/regress/regress-2322.js b/test/mjsunit/regress/regress-2243.js
similarity index 90%
copy from test/mjsunit/regress/regress-2322.js
copy to test/mjsunit/regress/regress-2243.js
index 1195bab67cb6b9123e93c3bd32135e972799e876..cdae91f3e67af8fe6b988803e47c826d344bacab 100644
--- a/test/mjsunit/regress/regress-2322.js
+++ b/test/mjsunit/regress/regress-2243.js
@@ -27,10 +27,5 @@
 
 // Flags: --harmony-scoping
 
-"use strict";
-
-assertThrows("'use strict'; for (let x in x);", ReferenceError);
-
-let s;
-for (let pppp in {}) {};
-assertThrows(function() { pppp = true }, ReferenceError);
+assertThrows("'use strict'; (function fooob() { fooob = 123; })", SyntaxError);
+assertThrows("(function f() { 'use strict'; f = 123; })", SyntaxError);