Support metadata on patches.

pkg/compiler/lib/src/tree/nodes.dart

Index: pkg/compiler/lib/src/tree/nodes.dart
diff --git a/pkg/compiler/lib/src/tree/nodes.dart b/pkg/compiler/lib/src/tree/nodes.dart
index 56f1f26bf4ff793d52df0cc9ec9e7bf4fc88a47b..6c4516b416efd886b4e4afb3fa48870660a0b5f5 100644
--- a/pkg/compiler/lib/src/tree/nodes.dart
+++ b/pkg/compiler/lib/src/tree/nodes.dart
@@ -1897,7 +1897,7 @@ class LabeledStatement extends Statement {
 }
 
 abstract class LibraryTag extends Node {
-  final Link<MetadataAnnotation> metadata;
+  final List<MetadataAnnotation> metadata;
 
   LibraryTag(this.metadata);
 
@@ -1915,7 +1915,7 @@ class LibraryName extends LibraryTag {
 
   LibraryName(this.libraryKeyword,
               this.name,
-              Link<MetadataAnnotation> metadata)
+              List<MetadataAnnotation> metadata)
     : super(metadata);
 
   bool get isLibraryName => true;
@@ -1942,7 +1942,7 @@ abstract class LibraryDependency extends LibraryTag {
 
   LibraryDependency(this.uri,
                     this.combinators,
-                    Link<MetadataAnnotation> metadata)
+                    List<MetadataAnnotation> metadata)
     : super(metadata);
 
   LibraryDependency asLibraryDependency() => this;
@@ -1962,7 +1962,7 @@ class Import extends LibraryDependency {
 
   Import(this.importKeyword, StringNode uri,
          this.prefix, NodeList combinators,
-         Link<MetadataAnnotation> metadata,
+         List<MetadataAnnotation> metadata,
          {this.isDeferred})
       : super(uri, combinators, metadata);
 
@@ -2027,7 +2027,7 @@ class Export extends LibraryDependency {
   Export(this.exportKeyword,
          StringNode uri,
          NodeList combinators,
-         Link<MetadataAnnotation> metadata)
+         List<MetadataAnnotation> metadata)
       : super(uri, combinators, metadata);
 
   bool get isExport => true;
@@ -2054,7 +2054,7 @@ class Part extends LibraryTag {
 
   final Token partKeyword;
 
-  Part(this.partKeyword, this.uri, Link<MetadataAnnotation> metadata)
+  Part(this.partKeyword, this.uri, List<MetadataAnnotation> metadata)
     : super(metadata);
 
   bool get isPart => true;
@@ -2075,7 +2075,7 @@ class PartOf extends Node {
 
   final Token partKeyword;
 
-  final Link<MetadataAnnotation> metadata;
+  final List<MetadataAnnotation> metadata;
 
   PartOf(this.partKeyword, this.name, this.metadata);