Resolve type arguments to generic methods.

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

 // Copyright (c) 2012, 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.
 
 import '../tokens/token.dart' show Token;
 import '../tokens/token_constants.dart' as Tokens
     show IDENTIFIER_TOKEN, KEYWORD_TOKEN, PLUS_TOKEN;
 import '../util/util.dart';
 import 'nodes.dart';
 
@@ skipping 439 matching lines @@
   unparseSendArgument(Send node, {bool spacesNeeded: false}) {
     if (node.argumentsNode == null) return;
 
     if (node.isIsNotCheck) {
       Send argNode = node.arguments.head;
       visit(argNode.selector);
       space();
       visit(argNode.receiver);
     } else {
       if (spacesNeeded) write(' ');
+      visit(node.typeArgumentsNode);

[eernst, 2016/11/30 10:39:01]

Yes! If this is used to format diagnostic messages to developers etc. then it is
definitely useful that we don't just drop the type arguments---that could be
quite confusing.

       visit(node.argumentsNode);
     }
   }
 
   visitSend(Send node) {
     Operator op = node.selector.asOperator();
     String opString = op != null ? op.source : null;
     bool spacesNeeded = minify
         ? identical(opString, 'is') || identical(opString, 'as')
         : (opString != null && !node.isPrefix && !node.isIndex);
@@ skipping 427 matching lines @@
   }
 
   visitStatement(Statement node) {
     throw 'internal error'; // Should not be called.
   }
 
   visitStringNode(StringNode node) {
     throw 'internal error'; // Should not be called.
   }
 }