Use a real program when compiling platform.dill.

pkg/fasta/lib/src/compile_platform.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library fasta.compile_platform;
 
 import 'dart:async' show
     Future;
 
 import 'dart:io' show
@@ skipping 73 matching lines @@
 main(List<String> arguments) async {
   Uri output = Uri.base.resolveUri(new Uri.file(arguments.single));
   DartOptions options = new DartOptions(
       strongMode: false, sdk: await dartAotSdk.value, packagePath: null);
   Repository repository = new Repository();
   DartLoader loader = new DartLoader(repository, options, null,
       ignoreRedirectingFactories: false,
       dartSdk: createDartSdk(options.sdk, strongMode: options.strongMode));
   Target target = getTarget(
       "vm", new TargetFlags(strongMode: options.strongMode));
-  Library dummyLibrary = repository.getLibraryReference(Uri.parse("dummy:"))
-      ..isExternal = false;
-  Program program =
-      loader.loadProgram(dummyLibrary.importUri, target: target);
+  Program program = loader.loadProgram(
+      Uri.base.resolve("pkg/fasta/test/platform.dart"), target: target);
+  if (loader.errors.isNotEmpty) {
+    inputError(null, null, loader.errors.join("\n"));
+  }
+  Library mainLibrary = program.mainMethod.enclosingLibrary;
+  program.uriToSource.remove(mainLibrary.fileUri);
   program = new Program(
       program.libraries.where(
           (Library l) => l.importUri.scheme == "dart").toList(),
       program.uriToSource);
-  if (loader.errors.isNotEmpty) {
-    inputError(null, null, loader.errors.join("\n"));
-  }
   target.transformProgram(program);
   for (LibraryElement analyzerLibrary in loader.libraryElements) {
     Library library = loader.getLibraryReference(analyzerLibrary);
     StringBuffer sb = new StringBuffer();
     if (analyzerLibrary.exports.isNotEmpty) {
       Source source;
       int offset;
       for (ExportElement export in analyzerLibrary.exports) {
         source ??= export.source;
         offset ??= export.nameOffset;
@@ skipping 13 matching lines @@
       library.addMember(new Field(exports, isStatic: true, isConst: true,
               initializer: literal, fileUri: "${new Uri.file(source.fullName)}")
           ..fileOffset = offset);
     }
   }
 
   IOSink sink = new File.fromUri(output).openWrite();
   new BinaryPrinter(sink).writeProgramFile(program);
   await sink.close();
 }