[flutter_tools] pass --compact-async to frontend_server (#104026)

Author: Jonah Williams

packages/flutter_tools/lib/src/compile.dart

@@ -19,6 +19,12 @@ import 'base/platform.dart';
 import 'build_info.dart';
 import 'convert.dart';
 
+/// Opt-in changes to the dart compilers.
+const List<String> kDartCompilerExperiments = <String>[
+  // improve AOT code size.
+  '--compact-async',
+];
+
 /// The target model describes the set of core libraries that are available within
 /// the SDK.
 class TargetModel {
@@ -183,11 +189,13 @@ List<String> buildModeOptions(BuildMode mode, List<String> dartDefines) {
           '-Ddart.vm.profile=true',
         if (!dartDefines.any((String define) => define.startsWith('dart.vm.product')))
           '-Ddart.vm.product=false',
+        ...kDartCompilerExperiments,
       ];
     case BuildMode.release:
       return <String>[
         '-Ddart.vm.profile=false',
         '-Ddart.vm.product=true',
+        ...kDartCompilerExperiments,
       ];
   }
   throw Exception('Unknown BuildMode: $mode');

packages/flutter_tools/test/general.shard/compile_batch_test.dart

@@ -197,6 +197,7 @@ void main() {
           '--no-print-incremental-dependencies',
           '-Ddart.vm.profile=true',
           '-Ddart.vm.product=false',
+          '--compact-async',
           '--no-link-platform',
           '--aot',
           '--tfa',
@@ -244,6 +245,7 @@ void main() {
           '--no-print-incremental-dependencies',
           '-Ddart.vm.profile=false',
           '-Ddart.vm.product=true',
+          '--compact-async',
           '--no-link-platform',
           '--aot',
           '--tfa',

packages/flutter_tools/test/general.shard/compile_test.dart

@@ -105,11 +105,13 @@ void main() {
   testWithoutContext('buildModeOptions removes matching profile define in profile mode', () {
     expect(buildModeOptions(BuildMode.profile, <String>['dart.vm.profile=true']), <String>[
       '-Ddart.vm.product=false',
+      '--compact-async'
     ]);
   });
 
   testWithoutContext('buildModeOptions removes both matching profile and release define in profile mode', () {
     expect(buildModeOptions(BuildMode.profile, <String>['dart.vm.profile=false', 'dart.vm.product=true']), <String>[
+      '--compact-async'
     ]);
   });
 }