Change the order of arguments of the (One|Two)ByteSeqStringSetChar intrinsic.

test/mjsunit/regress/regress-seqstrsetchar-ex1.js

Index: test/mjsunit/regress/regress-seqstrsetchar-ex1.js
diff --git a/test/mjsunit/regress/regress-seqstrsetchar-ex1.js b/test/mjsunit/regress/regress-seqstrsetchar-ex1.js
index c85cf56e0cf34b46e7a9435b5e0a7b8f843c436c..1fd8d810b325269001a8984cc9036ac2559d4139 100644
--- a/test/mjsunit/regress/regress-seqstrsetchar-ex1.js
+++ b/test/mjsunit/regress/regress-seqstrsetchar-ex1.js
@@ -47,7 +47,7 @@ function StringFromCharCode(code) {
   var two_byte = %NewString(n - i, false);
   for (var j = 0; i < n; i++, j++) {
     var code = %_Arguments(i);
-    %_TwoByteSeqStringSetChar(two_byte, j, code);
+    %_TwoByteSeqStringSetChar(j, code, two_byte);
   }
   return one_byte + two_byte;
 }