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

pkg/analyzer_experimental/test/generated/resolver_test.dart

Index: pkg/analyzer_experimental/test/generated/resolver_test.dart
diff --git a/pkg/analyzer_experimental/test/generated/resolver_test.dart b/pkg/analyzer_experimental/test/generated/resolver_test.dart
index 829f7ff99be2b04fe193acab98935cf179c2ebc0..fd28a6685adf725407d9ce40c9413999ed402ec6 100644
--- a/pkg/analyzer_experimental/test/generated/resolver_test.dart
+++ b/pkg/analyzer_experimental/test/generated/resolver_test.dart
@@ -2230,7 +2230,7 @@ class CompileTimeErrorCodeTest extends ResolverTestCase {
     verify([source]);
   }
   void fail_prefixCollidesWithTopLevelMembers() {
-    Source source = addSource(EngineTestCase.createSource(["import 'dart:uri' as uri;", "var uri = null;"]));
+    Source source = addSource(EngineTestCase.createSource(["import 'dart:uft' as utf;", "var utf = null;"]));
     resolve(source, []);
     assertErrors([CompileTimeErrorCode.PREFIX_COLLIDES_WITH_TOP_LEVEL_MEMBER]);
     verify([source]);
@@ -6765,4 +6765,4 @@ main() {
 //  StaticTypeWarningCodeTest.dartSuite();
 //  StaticWarningCodeTest.dartSuite();
 //  TypePropagationTest.dartSuite();
-}
+}