Add a way to use shared CanonicalName root to deserialize Program.

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 db0b740b2d8b773c38b263ba1a378df3e61934ee..3a973076d520e2b161daac3a325ba2a5adef7d2a 100644
--- a/pkg/front_end/lib/src/fasta/fasta.dart
+++ b/pkg/front_end/lib/src/fasta/fasta.dart
@@ -112,7 +112,7 @@ class CompileTask {
   CompileTask(this.c, this.ticker);
 
   DillTarget createDillTarget(TranslateUri uriTranslator) {
-    return new DillTarget(ticker, uriTranslator);
+    return new DillTarget(null, ticker, uriTranslator);
   }
 
   KernelTarget createKernelTarget(
@@ -179,7 +179,7 @@ Future<CompilationResult> parseScript(
       TranslateUri uriTranslator =
           await TranslateUri.parse(PhysicalFileSystem.instance, null, packages);
       final Ticker ticker = new Ticker(isVerbose: verbose);
-      final DillTarget dillTarget = new DillTarget(ticker, uriTranslator);
+      final DillTarget dillTarget = new DillTarget(null, ticker, uriTranslator);
       _appendDillForUri(dillTarget, patchedSdk.resolve('platform.dill'));
       final KernelTarget kernelTarget = new KernelTarget(
           PhysicalFileSystem.instance, dillTarget, uriTranslator, strongMode);
@@ -250,7 +250,7 @@ Future writeDepsFile(Uri script, Uri depsFile, Uri output,
     TranslateUri uriTranslator = await TranslateUri.parse(
         c.fileSystem, c.options.sdk, c.options.packages);
     ticker.logMs("Read packages file");
-    DillTarget dillTarget = new DillTarget(ticker, uriTranslator);
+    DillTarget dillTarget = new DillTarget(null, ticker, uriTranslator);
     _appendDillForUri(dillTarget, platform);
     KernelTarget kernelTarget = new KernelTarget(PhysicalFileSystem.instance,
         dillTarget, uriTranslator, false, c.uriToSource);
@@ -268,6 +268,7 @@ Future writeDepsFile(Uri script, Uri depsFile, Uri output,
 void _appendDillForUri(DillTarget dillTarget, Uri uri) {
   var bytes = new File.fromUri(uri).readAsBytesSync();
   var platformProgram = loadProgramFromBytes(bytes);
+  platformProgram.unbindCanonicalNames();
   dillTarget.loader.appendLibraries(platformProgram);
 }