Merge the dart:uri library into dart:core and update the Uri class

runtime/bin/main.cc

Index: runtime/bin/main.cc
diff --git a/runtime/bin/main.cc b/runtime/bin/main.cc
index 5bfc07986ecef6e8d1145b561958e6a227538129..6f139b776258cbf0ac66c01efa002ed0dc7cf248 100644
--- a/runtime/bin/main.cc
+++ b/runtime/bin/main.cc
@@ -454,9 +454,6 @@ static Dart_Isolate CreateIsolateAndSetupHelper(const char* script_uri,
   // Prepare builtin and its dependent libraries for use to resolve URIs.
   // The builtin library is part of the core snapshot and would already be
   // available here in the case of script snapshot loading.
-  Dart_Handle uri_url = DartUtils::NewString(DartUtils::kUriLibURL);
-  Dart_Handle uri_lib = Dart_LookupLibrary(uri_url);
-  CHECK_RESULT(uri_lib);
   Dart_Handle builtin_lib =
       Builtin::LoadAndCheckLibrary(Builtin::kBuiltinLibrary);
   CHECK_RESULT(builtin_lib);