Reapply "Use backend targets to run Kernel transformations in Fasta"

pkg/front_end/lib/kernel_generator.dart

Index: pkg/front_end/lib/kernel_generator.dart
diff --git a/pkg/front_end/lib/kernel_generator.dart b/pkg/front_end/lib/kernel_generator.dart
index eec59026300a31c26820e2466f6114eaa1247ada..248d13d447de9e5ec40a29f6af52f7b16fd4db33 100644
--- a/pkg/front_end/lib/kernel_generator.dart
+++ b/pkg/front_end/lib/kernel_generator.dart
@@ -13,6 +13,7 @@ import 'src/fasta/dill/dill_target.dart' show DillTarget;
 import 'src/fasta/errors.dart' show InputError;
 import 'src/fasta/kernel/kernel_target.dart' show KernelTarget;
 import 'package:kernel/kernel.dart' show Program;
+import 'package:kernel/target/targets.dart' show TargetFlags;
 import 'src/fasta/ticker.dart' show Ticker;
 import 'src/fasta/translate_uri.dart' show TranslateUri;
 import 'src/simple_error.dart';
@@ -52,15 +53,16 @@ Future<Program> kernelForProgram(Uri source, CompilerOptions options) async {
   try {
     TranslateUri uriTranslator = await pOptions.getUriTranslator();
 
-    var dillTarget =
-        new DillTarget(new Ticker(isVerbose: false), uriTranslator, "vm");
+    var dillTarget = new DillTarget(
+        new Ticker(isVerbose: false), uriTranslator, "vm_fasta",
+        flags: new TargetFlags(strongMode: options.strongMode));
     var summary = await pOptions.sdkSummaryProgram;
     if (summary != null) {
       dillTarget.loader.appendLibraries(summary);
     }
 
-    var kernelTarget = new KernelTarget(
-        options.fileSystem, dillTarget, uriTranslator, options.strongMode);
+    var kernelTarget =
+        new KernelTarget(options.fileSystem, dillTarget, uriTranslator);
     kernelTarget.read(source);
 
     await dillTarget.buildOutlines();
@@ -148,8 +150,9 @@ Future<Program> kernelForBuildUnit(
   try {
     TranslateUri uriTranslator = await pOptions.getUriTranslator();
 
-    var dillTarget =
-        new DillTarget(new Ticker(isVerbose: false), uriTranslator, "vm");
+    var dillTarget = new DillTarget(
+        new Ticker(isVerbose: false), uriTranslator, "vm_fasta",
+        flags: new TargetFlags(strongMode: options.strongMode));
     var summary = await pOptions.sdkSummaryProgram;
     if (summary != null) {
       dillTarget.loader.appendLibraries(summary);
@@ -164,8 +167,8 @@ Future<Program> kernelForBuildUnit(
 
     await dillTarget.buildOutlines();
 
-    var kernelTarget = new KernelTarget(
-        options.fileSystem, dillTarget, uriTranslator, options.strongMode);
+    var kernelTarget =
+        new KernelTarget(options.fileSystem, dillTarget, uriTranslator);
     sources.forEach(kernelTarget.read);
     await kernelTarget.buildOutlines();