Revert "Tweak public APIs and use them in patch_sdk, dart2js, and kernel-service."

pkg/kernel/lib/target/targets.dart

Index: pkg/kernel/lib/target/targets.dart
diff --git a/pkg/kernel/lib/target/targets.dart b/pkg/kernel/lib/target/targets.dart
index 3227f012c7b72a3ae7ef275653378886a0a37049..c47c117fe972d1c61487e542d1d93fa44f648396 100644
--- a/pkg/kernel/lib/target/targets.dart
+++ b/pkg/kernel/lib/target/targets.dart
@@ -121,29 +121,6 @@ abstract class Target {
   void performGlobalTransformations(CoreTypes coreTypes, Program program,
       {void logger(String msg)});
 
-  /// Whether a platform library may define a restricted type, such as `bool`,
-  /// `int`, `double`, `num`, and `String`.
-  ///
-  /// By default only `dart:core` may define restricted types, but some target
-  /// implementations override this.
-  bool mayDefineRestrictedType(Uri uri) =>
-      uri.scheme == 'dart' && uri.path == 'core';
-
-  /// Whether the `native` language extension is supported within [library].
-  ///
-  /// The `native` language extension is not part of the language specification,
-  /// it means something else to each target, and it is enabled under different
-  /// circumstances for each target implementation. For example, the VM target
-  /// enables it everywhere because of existing support for "dart-ext:" native
-  /// extensions, but targets like dart2js only enable it on the core libraries.
-  bool enableNative(Uri uri) => false;
-
-  /// There are two variants of the `native` language extension. The VM expects
-  /// the native token to be followed by string, whereas dart2js and DDC do not.
-  // TODO(sigmund, ahe): ideally we should remove the `native` syntax, if not,
-  // we should at least unify the VM and non-VM variants.
-  bool get nativeExtensionExpectsString => false;
-
   /// Builds an expression that instantiates an [Invocation] that can be passed
   /// to [noSuchMethod].
   Expression instantiateInvocation(CoreTypes coreTypes, Expression receiver,