Update 'dump-info' usage for dart2js builds (#156187)

Dart2js updated its CLI to support generating a 'dump-info' json file by passing a "--stage" option. The "dump-info-all" stage performs a full compilation (from the provided dill) and then also generates the dump info file.

Tested via the `flutter-dev` CLI locally. This results in the same output but with the addition of an extra `main.dart.js.info.json` file.

Author: biggs0125

packages/flutter_tools/lib/src/web/compiler_config.dart

@@ -115,7 +115,7 @@ class JsCompilerConfig extends WebCompilerConfig {
         if (buildMode != BuildMode.release) '--no-minify',
         ...toSharedCommandOptions(buildMode),
         '-O$optimizationLevel',
-        if (dumpInfo) '--dump-info',
+        if (dumpInfo) '--stage=dump-info-all',
         if (noFrequencyBasedMinification) '--no-frequency-based-minification',
         if (csp) '--csp',
       ];

packages/flutter_tools/test/general.shard/build_system/targets/web_test.dart

@@ -953,7 +953,7 @@ void main() {
         '--no-minify',
         '--no-source-maps',
         '-O4',
-        '--dump-info',
+        '--stage=dump-info-all',
         '-o',
         environment.buildDir.childFile('main.dart.js').absolute.path,
         environment.buildDir.childFile('app.dill').absolute.path,