Assert to protect against polymorphic string loads fires on valid stores.

test/mjsunit/regress/regress-435477.js

Index: test/mjsunit/regress/regress-435477.js
diff --git a/test/mjsunit/regress/regress-alloc-smi-check.js b/test/mjsunit/regress/regress-435477.js
similarity index 66%
copy from test/mjsunit/regress/regress-alloc-smi-check.js
copy to test/mjsunit/regress/regress-435477.js
index 295048a13ef862ceb21939de104e7968dd7772da..0a150002c9a1e692bd9e3bc3c94e3d2bffa8eca4 100644
--- a/test/mjsunit/regress/regress-alloc-smi-check.js
+++ b/test/mjsunit/regress/regress-435477.js
@@ -1,16 +1,16 @@
 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-//
-// Flags: --allow-natives-syntax
 
-var x = {};
+// Flags: --allow-natives-syntax
+var a = new Array(128);
 
-function f(a) {
-  a[200000000] = x;
+function f(a, base) {
+  a[base] = 2;
 }
 
-f(new Array(100000));
-f([]);
+f(a, undefined);
+f("r12", undefined);
+f(a, 0);
 %OptimizeFunctionOnNextCall(f);
-f([]);
+f(a, 0);