More tests updated to optimize code (Part 2).

tests/language/load_to_load_forwarding_vm_test.dart

Index: tests/language/load_to_load_forwarding_vm_test.dart
===================================================================
--- tests/language/load_to_load_forwarding_vm_test.dart	(revision 24922)
+++ tests/language/load_to_load_forwarding_vm_test.dart	(working copy)
@@ -231,13 +231,13 @@
   u32List[1] = 0x3FFFFFFF;
   u32List[2] = 0x7FFFFFFF;
 
-  for (var i = 0; i < 4000; i++) {
+  for (var i = 0; i < 20; i++) {
     testPhiConvertions(true, u32List);
     testPhiConvertions(false, u32List);
   }
 
   final escape = new List(1);
-  for (var i = 0; i < 10000; i++) {
+  for (var i = 0; i < 20; i++) {
     fakeAliasing(escape);
   }
 }