Merge TRUNCDIV and MOD into TRUNCDIV_MOD single operation.

tests/language/modulo_test.dart

Index: tests/language/modulo_test.dart
===================================================================
--- tests/language/modulo_test.dart	(revision 30236)
+++ tests/language/modulo_test.dart	(working copy)
@@ -11,23 +11,18 @@
   for (int i = -30; i < 30; i++) {
     Expect.equals(i % 256, foo(i));
     Expect.equals(i % -256, boo(i));
-    try {
-      hoo(i);
-      Expect.fail("Exception expected.");
-    } catch (e) {}
+    Expect.throws(() => hoo(i), (e) => e is IntegerDivisionByZeroException);
+    
+    Expect.equals(i ~/ 256 + i % 256, fooTwo(i));
+    Expect.equals(i ~/ -256 + i % -256, booTwo(i));
+    Expect.throws(() => hooTwo(i), (e) => e is IntegerDivisionByZeroException);
   }
 }
 
-foo(i) {
-  return i % 256;  // This will get optimized to AND instruction.
-}
+foo(i) => i % 256;  // This will get optimized to AND instruction.
+boo(i) => i % -256;
+hoo(i) => i % 0;
 
-
-boo(i) {
-  return i % -256;
-}
-
-
-hoo(i) {
-  return i % 0;
-}
+fooTwo(i) => i ~/ 256 + i % 256;
+booTwo(i) => i ~/ -256 + i % -256;
+hooTwo(i) => i ~/ 0 + i % 0;