Support "--checked" in pub run and global run.

test/run/runs_the_script_in_unchecked_mode_test.dart

Index: test/run/runs_the_script_in_unchecked_mode_test.dart
diff --git a/test/run/runs_the_script_in_checked_mode_test.dart b/test/run/runs_the_script_in_unchecked_mode_test.dart
similarity index 71%
copy from test/run/runs_the_script_in_checked_mode_test.dart
copy to test/run/runs_the_script_in_unchecked_mode_test.dart
index 28a0fd946ba1f762d9f651d6a3d121a805f12f9c..cdb2e52a3662e4a8187c315fad261559833a7172 100644
--- a/test/run/runs_the_script_in_checked_mode_test.dart
+++ b/test/run/runs_the_script_in_unchecked_mode_test.dart
@@ -10,11 +10,12 @@ import '../test_pub.dart';
 const SCRIPT = """
 main() {
   int a = true;
+  print("no checks");
 }
 """;
 
 main() {
-  integration('runs the script in checked mode by default', () {
+  integration('runs the script in unchecked mode by default', () {
     d.dir(appPath, [
       d.appPubspec(),
       d.dir("bin", [
@@ -22,8 +23,6 @@ main() {
       ])
     ]).create();
 
-    schedulePub(args: ["run", "bin/script"],
-        error: contains("'bool' is not a subtype of type 'int' of 'a'"),
-        exitCode: 255);
+    schedulePub(args: ["run", "bin/script"], output: contains("no checks"));
   });
 }