Implement the kernel_generator API using fasta

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

Index: pkg/front_end/lib/src/fasta/fasta.dart
diff --git a/pkg/front_end/lib/src/fasta/fasta.dart b/pkg/front_end/lib/src/fasta/fasta.dart
index ecd2c512f7dc9398accca96217b06050abdecff0..c42058949ab626e87c808ef7f4f98e9397d63861 100644
--- a/pkg/front_end/lib/src/fasta/fasta.dart
+++ b/pkg/front_end/lib/src/fasta/fasta.dart
@@ -173,8 +173,6 @@ Future<CompilationResult> parseScript(
           formatUnexpected(patchedSdk, -1, "Patched sdk directory not found."));
     }
 
-    Target target = getTarget("vm", new TargetFlags(strongMode: false));
-
     Program program;
     try {
       TranslateUri uriTranslator = await TranslateUri.parse(null, packages);
@@ -201,6 +199,7 @@ Future<CompilationResult> parseScript(
     }
 
     // Perform target-specific transformations.
+    Target target = getTarget("vm", new TargetFlags(strongMode: false));
     target.performModularTransformations(program);
     target.performGlobalTransformations(program);