[SDK] Fixes run_appended_aotsnapshot_test on Windows.

Bug: #38974
Change-Id: I5fafb29252f20a536b5543d309ddeb4ccd3421ec
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/122145
Auto-Submit: Clement Skau <[email protected]>
Commit-Queue: Daco Harkes <[email protected]>
Reviewed-by: Daco Harkes <[email protected]>

Author: Clement Skau

runtime/tests/vm/dart/run_appended_aot_snapshot_test.dart

@@ -63,7 +63,7 @@ Future<void> main(List<String> args) async {
       Map<String, String> environment = {'PATH': tmp};
       final runResult = await runBinary(
           'run appended aot snapshot from PATH', exeName, ['--child'],
-          environment: environment);
+          environment: environment, runInShell: true);
       expectOutput('Hello, Appended AOT', runResult);
     }
 
@@ -76,7 +76,8 @@ Future<void> main(List<String> args) async {
           'run appended aot snapshot without extension',
           exeNameWithoutExt,
           ['--child'],
-          environment: environment);
+          environment: environment,
+          runInShell: true);
       expectOutput('Hello, Appended AOT', runResult);
     }
   });

runtime/tests/vm/dart/snapshot_test_helper.dart

@@ -73,10 +73,10 @@ Future<Result> runGenSnapshot(String prefix, List<String> arguments) {
 }
 
 Future<Result> runBinary(String prefix, String binary, List<String> arguments,
-    {Map<String, String> environment}) async {
+    {Map<String, String> environment, bool runInShell: false}) async {
   print("+ $binary " + arguments.join(" "));
-  final processResult =
-      await Process.run(binary, arguments, environment: environment);
+  final processResult = await Process.run(binary, arguments,
+      environment: environment, runInShell: runInShell);
   final result =
       new Result('[$prefix] ${binary} ${arguments.join(' ')}', processResult);