unfork DDC's copy of most SDK libraries

pkg/dev_compiler/tool/input_sdk/private/annotations.dart

 // 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.
 
 part of dart._js_helper;
 
+/// Tells the optimizing compiler that the annotated method has no
+/// side-effects. Allocations don't count as side-effects, since they can be
+/// dropped without changing the semantics of the program.
+///
+/// Requires @NoInline() to function correctly.
+class NoSideEffects {
+  const NoSideEffects();
+}
+
 /// Tells the optimizing compiler that the annotated method cannot throw.
 /// Requires @NoInline() to function correctly.
 class NoThrows {
   const NoThrows();
 }
 
 /// Tells the optimizing compiler to not inline the annotated method.
 class NoInline {
   const NoInline();
 }
 
+/// Tells the optimizing compiler to always inline the annotated method.
+class ForceInline {
+  const ForceInline();
+}
+
 /// Marks a class as native and defines its JavaScript name(s).
 class Native {
   final String name;
   const Native(this.name);
 }
 
 class JsPeerInterface {
   /// The JavaScript type that we should match the API of.
   /// Used for classes where Dart subclasses should be callable from JavaScript
   /// matching the JavaScript calling conventions.
   final String name;
   const JsPeerInterface({this.name});
 }
 
 /// A Dart interface may only be implemented by a native JavaScript object
 /// if it is marked with this annotation.
 class SupportJsExtensionMethods {
   const SupportJsExtensionMethods();
 }