Correctly set root_library based on the application script URI instead of looking for the library t…

runtime/bin/gen_snapshot.cc

 // Copyright (c) 2013, 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.
 
 // Generate a snapshot file after loading all the scripts specified on the
 // command line.
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 1731 matching lines @@
     CHECK_RESULT(result);
 
     if (commandline_packages_file != NULL) {
       AddDependency(commandline_packages_file);
     }
 
     Dart_QualifiedFunctionName* entry_points =
         ParseEntryPointsManifestIfPresent();
 
     if (kernel_program != NULL) {
-      Dart_Handle library = Dart_LoadKernel(kernel_program);
-      if (Dart_IsError(library)) FATAL("Failed to load app from Kernel IR");
+      Dart_Handle resolved_uri = ResolveUriInWorkingDirectory(app_script_name);
+      CHECK_RESULT(resolved_uri);
+      Dart_Handle library =
+          Dart_LoadScript(resolved_uri, Dart_Null(),
+                          reinterpret_cast<Dart_Handle>(kernel_program), 0, 0);
+      CHECK_RESULT(library);
     } else {
       // Set up the library tag handler in such a manner that it will use the
       // URL mapping specified on the command line to load the libraries.
       result = Dart_SetLibraryTagHandler(CreateSnapshotLibraryTagHandler);
       CHECK_RESULT(result);
     }
 
     SetupStubNativeResolversForPrecompilation(entry_points);
 
     SetupStubNativeResolvers();
@@ skipping 71 matching lines @@
   delete mapped_isolate_snapshot_instructions;
   return 0;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   return dart::bin::main(argc, argv);
 }