Setup correct scope for initializers and complain about fields initialized more than once.

pkg/front_end/lib/src/fasta/source/outline_builder.dart

 // Copyright (c) 2016, 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.
 
 library fasta.outline_builder;
 
 import 'package:kernel/ast.dart' show ProcedureKind;
 
 import '../fasta_codes.dart' show FastaMessage, codeExpectedBlockToSkip;
 
@@ skipping 609 matching lines @@
     }
     List<MetadataBuilder> metadata = pop();
     library.addFunctionTypeAlias(
         metadata, returnType, name, typeVariables, formals, charOffset);
     checkEmpty(typedefKeyword.charOffset);
   }
 
   @override
   void endTopLevelFields(int count, Token beginToken, Token endToken) {
     debugEvent("endTopLevelFields");
-    List namesOffsetsAndInitializers = popList(count * 4);
+    List fieldsInfo = popList(count * 4);
     TypeBuilder type = pop();
     int modifiers = Modifier.validate(pop());
     List<MetadataBuilder> metadata = pop();
-    library.addFields(metadata, modifiers, type, namesOffsetsAndInitializers);
+    library.addFields(metadata, modifiers, type, fieldsInfo);
     checkEmpty(beginToken.charOffset);
   }
 
   @override
   void endFields(int count, Token beginToken, Token endToken) {
     debugEvent("Fields");
-    List namesOffsetsAndInitializers = popList(count * 4);
+    List fieldsInfo = popList(count * 4);
     TypeBuilder type = pop();
     int modifiers = Modifier.validate(pop());
     List<MetadataBuilder> metadata = pop();
-    library.addFields(metadata, modifiers, type, namesOffsetsAndInitializers);
+    library.addFields(metadata, modifiers, type, fieldsInfo);
   }
 
   @override
   void endTypeVariable(Token token, Token extendsOrSuper) {
     debugEvent("endTypeVariable");
     TypeBuilder bound = pop();
     int charOffset = pop();
     String name = pop();
     // TODO(paulberry): type variable metadata should not be ignored.  See
     // dartbug.com/28981.
@@ skipping 61 matching lines @@
 
   @override
   void endRedirectingFactoryBody(Token beginToken, Token endToken) {
     debugEvent("RedirectingFactoryBody");
     push(MethodBody.RedirectingFactoryBody);
   }
 
   @override
   void endFieldInitializer(Token assignmentOperator, Token token) {
     debugEvent("FieldInitializer");
+    Token beforeLast = assignmentOperator.next;
+    Token next = beforeLast.next;
+    while (next != token && !next.isEof) {
+      // To avoid storing the rest of the token stream, we need to identify the
+      // token before [token]. That token will be the last token of the
+      // initializer expression and by setting its tail to EOF we only store
+      // the tokens for the expression.
+      // TODO(ahe): Might be clearer if this search was moved to
+      // `library.addFields`.
+      beforeLast = next;
+      next = next.next;
+    }
     push(assignmentOperator.next);
-    push(token);
+    push(beforeLast);
   }
 
   @override
   void handleNoFieldInitializer(Token token) {
     debugEvent("NoFieldInitializer");
     push(NullValue.FieldInitializer);
     push(NullValue.FieldInitializer);
   }
 
   @override
@@ skipping 59 matching lines @@
   Link<Token> handleMemberName(Link<Token> identifiers) {
     if (!enableNative || identifiers.isEmpty) return identifiers;
     return removeNativeClause(identifiers);
   }
 
   @override
   void debugEvent(String name) {
     // printEvent(name);
   }
 }