Clone platform in memory when testing.

pkg/front_end/lib/src/fasta/testing/suite.dart

Index: pkg/front_end/lib/src/fasta/testing/suite.dart
diff --git a/pkg/front_end/lib/src/fasta/testing/suite.dart b/pkg/front_end/lib/src/fasta/testing/suite.dart
index c651cb85577180b897cecb4fb2907dd6b401ea5f..a5e94376af3644b5ac6bb31b3b01266b4e892023 100644
--- a/pkg/front_end/lib/src/fasta/testing/suite.dart
+++ b/pkg/front_end/lib/src/fasta/testing/suite.dart
@@ -10,6 +10,9 @@ import 'dart:async' show
 import 'dart:convert' show
     JSON;
 
+import 'dart:typed_data' show
+    Uint8List;
+
 import 'package:analyzer/src/generated/sdk.dart' show
     DartSdk;
 
@@ -17,6 +20,18 @@ import 'package:kernel/ast.dart' show
     Library,
     Program;
 
+import 'package:kernel/binary/ast_from_binary.dart' show
+    BinaryBuilder;
+
+import 'package:kernel/binary/ast_to_binary.dart' show
+    BinaryPrinter;
+
+import 'package:kernel/binary/loader.dart' show
+    BinaryLoader;
+
+import 'package:kernel/kernel.dart' show
+    Repository;
+
 import 'package:kernel/analyzer/loader.dart' show
     DartLoader;
 
@@ -36,11 +51,12 @@ import '../errors.dart' show
     InputError;
 
 import 'kernel_chain.dart' show
+    BytesCollector,
     MatchExpectation,
     Print,
     Run,
-    Verify,
     TestContext,
+    Verify,
     WriteDill;
 
 import '../ticker.dart' show
@@ -97,7 +113,7 @@ class FeContext extends TestContext {
   final ExpectationSet expectationSet =
       new ExpectationSet.fromJsonList(JSON.decode(EXPECTATIONS));
 
-  Future<Program> platform;
+  Future<Uint8List> platform;
 
   FeContext(Uri sdk, Uri vm, Uri packages, bool strongMode,
       DartSdk dartSdk, bool updateExpectations, this.uriTranslator,
@@ -119,24 +135,29 @@ class FeContext extends TestContext {
     }
   }
 
-  Future<Program> createPlatform() {
-    return platform ??= new Future<Program>(() async {
+  Future<Program> createPlatform() async {
+    platform ??= new Future<Uint8List>(() async {
       DartLoader loader = await createLoader();
       Target target = getTarget(
           "vm", new TargetFlags(strongMode: options.strongMode));
       Program program = loader.loadProgram(
           Uri.base.resolve("pkg/fasta/test/platform.dart"), target: target);
-      target.performModularTransformations(program);
-      target.performGlobalTransformations(program);
       if (loader.errors.isNotEmpty) {
         throw loader.errors.join("\n");
       }
       Library mainLibrary = program.mainMethod.enclosingLibrary;
       program.uriToSource.remove(mainLibrary.fileUri);
-      return new Program(
+      Program platform = new Program(
           program.libraries.where((Library l) => l != mainLibrary).toList(),
           program.uriToSource);
+      target.performModularTransformations(platform);
+      target.performGlobalTransformations(platform);
+      BytesCollector sink = new BytesCollector();
+      new BinaryPrinter(sink).writeProgramFile(platform);
+      return sink.collect();
     });
+    BinaryLoader loader = new BinaryLoader(new Repository());
+    return new BinaryBuilder(loader, await platform).readProgramFile();
   }
 
   static Future<FeContext> create(Chain suite, Map<String, String> environment,