Don't constant fold operation if result is incompatible with it.

tests/language/vm/regress_22480_test.dart

Index: tests/language/vm/regress_22480_test.dart
diff --git a/tests/language/vm/uint32_right_shift_test.dart b/tests/language/vm/regress_22480_test.dart
similarity index 56%
copy from tests/language/vm/uint32_right_shift_test.dart
copy to tests/language/vm/regress_22480_test.dart
index 6c7ae5f29cffe51453661efa53f075e075366c84..3cbe98a93d74df0fb61d5bf1e916393e9f9f0b74 100644
--- a/tests/language/vm/uint32_right_shift_test.dart
+++ b/tests/language/vm/regress_22480_test.dart
@@ -5,16 +5,16 @@
 
 import 'package:expect/expect.dart';
 
-trunc(x) => x & 0xFFFFFFFF;
-
-foo(t, x) => t(x >> 15);
+test(j) {
+  var result = true;
+  j++;
+  for (var i = 0; i < 100; i++) {
+    result = (i < 50 || j < (1 << 32)) && result;
+  }
+  return result;
+}
 
 main() {
-  for (var i = 0; i < 20000; i++) {
-    Expect.equals(0x00010000, foo(trunc, 0x80000000));
-  }
-  for (var i = 0; i < 20000; i++) {
-    Expect.equals(0x10000000, foo(trunc, 0x80000000000));
-  }
+  Expect.isTrue(test(30));
 }