Fix windows extension

TEST=Not applicable, fixing existing test

Change-Id: Ie39b7d71fdd1260471f44d98b0f75fe2d5a39153
Bug: dart-lang/sdk#46970
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/211060
Commit-Queue: Michael Thomsen <[email protected]>
Reviewed-by: Alexander Markov <[email protected]>

Author: mit-mit

pkg/vm_snapshot_analysis/test/utils.dart

@@ -10,7 +10,7 @@ import 'package:test/test.dart';
 
 final dartCompile = () {
   final sdkBin = path.dirname(Platform.executable);
-  final dartCmd = path.join(sdkBin, Platform.isWindows ? 'dart.bat' : 'dart');
+  final dartCmd = path.join(sdkBin, Platform.isWindows ? 'dart.exe' : 'dart');
 
   if (!File(dartCmd).existsSync()) {
     throw 'Failed to locate `dart` in the SDK';