[builtins] Fix String.prototype.indexOf with negative positions

test/mjsunit/string-indexof-1.js

Index: test/mjsunit/string-indexof-1.js
diff --git a/test/mjsunit/string-indexof-1.js b/test/mjsunit/string-indexof-1.js
index d626c223822f1d8d11a7026907f196077c93fcc8..e403ec4dad524dad47199ab404ec2cb4cbbc9322 100644
--- a/test/mjsunit/string-indexof-1.js
+++ b/test/mjsunit/string-indexof-1.js
@@ -30,14 +30,25 @@ var s = "test test test";
 assertEquals(0, s.indexOf("t"));
 assertEquals(3, s.indexOf("t", 1));
 assertEquals(5, s.indexOf("t", 4));
+assertEquals(5, s.indexOf("t", 4.1));
+assertEquals(0, s.indexOf("t", 0));
+assertEquals(0, s.indexOf("t", -1));
+assertEquals(0, s.indexOf("t", -1));
+assertEquals(0, s.indexOf("t", -1.1));
+assertEquals(0, s.indexOf("t", -1073741825));
 assertEquals(1, s.indexOf("e"));
 assertEquals(2, s.indexOf("s"));
 
 assertEquals(5, s.indexOf("test", 4));
 assertEquals(5, s.indexOf("test", 5));
 assertEquals(10, s.indexOf("test", 6));
+assertEquals(10, s.indexOf("test", 6.0));
 assertEquals(0, s.indexOf("test", 0));
+assertEquals(0, s.indexOf("test", 0.0));
 assertEquals(0, s.indexOf("test", -1));
+assertEquals(-1, s.indexOf("not found", -1));
+assertEquals(0, s.indexOf("test", -1.0));
+assertEquals(0, s.indexOf("test", -1073741825));
 assertEquals(0, s.indexOf("test"));
 assertEquals(-1, s.indexOf("notpresent"));
 assertEquals(-1, s.indexOf());