Split getClosureRepresentationInfo into MemberEntity and (ir/ast) nodes

pkg/compiler/lib/src/dump_info.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.
 
 library dump_info;
 
 import 'dart:convert'
     show ChunkedConversionSink, JsonEncoder, StringConversionSink;
 
 import 'package:dart2js_info/info.dart';
@@ skipping 195 matching lines @@
 
   ClosureInfo visitClosureClassElement(ClosureClassElement element, _) {
     ClosureInfo closureInfo = new ClosureInfo(
         name: element.name,
         outputUnit: _unitInfoForElement(element),
         size: compiler.dumpInfoTask.sizeOf(element));
     _elementToInfo[element] = closureInfo;
 
     ClosureRepresentationInfo closureRepresentation = compiler
         .backendStrategy.closureDataLookup
-        .getClosureRepresentationInfo(element.methodElement);
+        .getClosureRepresentationInfo(element.node);
     assert(closureRepresentation.closureClassEntity == element);
 
     FunctionInfo functionInfo = this.process(closureRepresentation.callMethod);
     if (functionInfo == null) return null;
     closureInfo.function = functionInfo;
     functionInfo.parent = closureInfo;
 
     result.closures.add(closureInfo);
     return closureInfo;
   }
@@ skipping 392 matching lines @@
 
     ChunkedConversionSink<Object> sink = encoder.startChunkedConversion(
         new StringConversionSink.fromStringSink(buffer));
     sink.add(new AllInfoJsonCodec().encode(result));
     compiler.reporter.reportInfo(NO_LOCATION_SPANNABLE, MessageKind.GENERIC, {
       'text': "View the dumped .info.json file at "
           "https://dart-lang.github.io/dump-info-visualizer"
     });
   }
 }