Account for the snapshot of dartdevc in the Dart SDK changing from a JIT snapshot to an AOT snapshot (#3742)

Dart SDK is in the process of changing snapshots in the SDK from JIT snapshots to AOT snapshots.
This change ensures that the package will continue to work when that change happens.

Author: a-siva

build_web_compilers/CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 4.0.12-wip
 
 - Bump the min sdk to 3.5.0.
+- Account for dartdevc snapshot in the Dart SDK changing to an AOT snapshot.
 
 ## 4.0.11
 

build_web_compilers/lib/src/sdk_js_compile_builder.dart

@@ -86,8 +86,17 @@ Future<void> _createDevCompilerModule(
   try {
     // Use standalone process instead of the worker due to
     // https://github.com/dart-lang/sdk/issues/49441
-    result = await Process.run(p.join(sdkDir, 'bin', 'dart'), [
-      p.join(sdkDir, 'bin', 'snapshots', 'dartdevc.dart.snapshot'),
+    var snapshotPath =
+        p.join(sdkDir, 'bin', 'snapshots', 'dartdevc_aot.dart.snapshot');
+    var execSuffix = Platform.isWindows ? '.exe' : '';
+    var dartPath = p.join(sdkDir, 'bin', 'dartaotruntime$execSuffix');
+    if (!File(snapshotPath).existsSync()) {
+      snapshotPath =
+          p.join(sdkDir, 'bin', 'snapshots', 'dartdevc.dart.snapshot');
+      dartPath = p.join(sdkDir, 'bin', 'dart$execSuffix');
+    }
+    result = await Process.run(dartPath, [
+      snapshotPath,
       '--multi-root-scheme=org-dartlang-sdk',
       '--modules=amd',
       if (canaryFeatures) '--canary',