Fix zero_termination tests in the bots (fixes #27066)

tests/compiler/dart2js/zero_termination_test.dart

Index: tests/compiler/dart2js/zero_termination_test.dart
diff --git a/tests/compiler/dart2js/zero_termination_test.dart b/tests/compiler/dart2js/zero_termination_test.dart
index fbfeab756a0d2f6ddd1743c8115e3901b432c878..9581e48a64bb036ac8c731716672e3c3ac58429a 100644
--- a/tests/compiler/dart2js/zero_termination_test.dart
+++ b/tests/compiler/dart2js/zero_termination_test.dart
@@ -47,11 +47,14 @@ void cleanup() {
 }
 
 Future launchDart2Js(args) {
-  String ext = Platform.isWindows ? '.bat' : '';
-  String command =
-      path.normalize(path.join(path.fromUri(Platform.script),
-                    '../../../../sdk/bin/dart2js${ext}'));
-  return Process.run(command, args, stdoutEncoding: null);
+  String executable = Platform.executable;
+  String command = path.join(path.dirname(executable), 'dart2js');
+  String dart2jsPath = path.normalize(

[Bill Hesse, 2016/08/12 19:01:31]

Maybe check if this exists, and don't fail if it is missing?

But I'm happy with changing tests so they only work when run from an SDK, not
from executables and scripts all over the checkout.

[Siggi Cherem (dart-lang), 2016/08/12 20:21:14]

I'd be afraid that the test would be "passing" but not running in that case.

+      path.join(path.fromUri(Platform.script),
+        '../../../../pkg/compiler/lib/src/dart2js.dart'));
+  List allArgs = ['--package-root=${Platform.packageRoot}',

[Bill Hesse, 2016/08/12 19:01:31]

I'm just working on removing packageRoot from test scripts today.  These will
soon be run with a package spec file, not a package root.

[Siggi Cherem (dart-lang), 2016/08/12 20:21:14]

good point - we should fix it to pass along whichever was specified in the first
place.

+       dart2jsPath]..addAll(args);
+  return Process.run(Platform.executable, allArgs, stdoutEncoding: null);
 }
 
 void check(ProcessResult result) {