Perform string add in generated code on IA-32 platforms...

test/mjsunit/string-add.js

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 155 matching lines @@
   assertEquals("stry42", resyw, "swyw");
   assertEquals("strz42", reszx, "swzx");
   assertEquals("strzstry", reszy, "swzy");
   assertEquals("strzstrz", reszz, "swzz");
   assertEquals("strz42", reszw, "swzw");
   assertEquals(84, reswx, "swwx");
   assertEquals("42stry", reswy, "swwy");
   assertEquals("42strz", reswz, "swwz");
   assertEquals(84, resww, "swww");
 })(1);
+
+// Generate ascii and non ascii strings from length 0 to 20.
+var ascii = 'aaaaaaaaaaaaaaaaaaaa';
+var non_ascii = '\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234\u1234';
+assertEquals(20, ascii.length);
+assertEquals(20, non_ascii.length);
+var a = Array(21);
+var b = Array(21);
+for (var i = 0; i <= 20; i++) {
+  a[i] = ascii.substring(0, i);
+  b[i] = non_ascii.substring(0, i);
+}
+
+// Add ascii and non-ascii strings generating strings with length from 0 to 20.
+for (var i = 0; i <= 20; i++) {
+  for (var j = 0; j < i; j++) {
+    assertEquals(a[i], a[j] + a[i - j])
+    assertEquals(b[i], b[j] + b[i - j])
+  }
+}