unfork DDC's copy of most SDK libraries

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

Index: pkg/dev_compiler/tool/input_sdk/private/annotations.dart
diff --git a/pkg/dev_compiler/tool/input_sdk/private/annotations.dart b/pkg/dev_compiler/tool/input_sdk/private/annotations.dart
index b7cc970ace3e42e3478ed72880e7959d125656ff..f4a34fa63e5fee5fcb9deda0ee79efc886ce8681 100644
--- a/pkg/dev_compiler/tool/input_sdk/private/annotations.dart
+++ b/pkg/dev_compiler/tool/input_sdk/private/annotations.dart
@@ -4,6 +4,15 @@
 
 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 {
@@ -15,6 +24,11 @@ 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;