Add more tests for closures and change closure indexing to be by FunctionExpression or FunctionDecl…

tests/compiler/dart2js/equivalence/id_equivalence_helper.dart

 // Copyright (c) 2017, 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 'dart:async';
 import 'dart:io';
 
 import 'package:compiler/src/common.dart';
 import 'package:compiler/src/common_elements.dart';
 import 'package:compiler/src/compiler.dart';
@@ skipping 193 matching lines @@
       annotatedCode, computeMemberData, compileFunction,
       options: options, verbose: verbose);
 
   data.actualMap.forEach((Id id, ActualData actualData) {
     String actual = actualData.value;
     if (!data.expectedMap.containsKey(id)) {
       if (actual != '') {
         reportHere(
             data.compiler.reporter,
             actualData.sourceSpan,
-            'Id $id for ${actualData.object} '
+            'Id $id = ${actual} for ${actualData.object} '
             '(${actualData.object.runtimeType}) '
             'not expected in ${data.expectedMap.keys}');
         print('--annotations diff--------------------------------------------');
         print(data.diffCode);
         print('--------------------------------------------------------------');
       }
       Expect.equals('', actual);
     } else {
-      String expected = data.expectedMap.remove(id);
+      String expected = data.expectedMap[id];
       if (actual != expected) {
         reportHere(
             data.compiler.reporter,
             actualData.sourceSpan,
             'Object: ${actualData.object} (${actualData.object.runtimeType}), '
             'expected: ${expected}, actual: ${actual}');
         print('--annotations diff--------------------------------------------');
         print(data.diffCode);
         print('--------------------------------------------------------------');
       }
       Expect.equals(expected, actual);
     }
   });
 
+  Set<Id> missingIds = new Set<Id>();
   data.expectedMap.forEach((Id id, String expected) {
-    reportHere(
-        data.compiler.reporter,
-        computeSpannable(data.elementEnvironment, data.mainUri, id),
-        'Expected $expected for id $id missing in ${data.actualMap.keys}');
+    if (!data.actualMap.containsKey(id)) {
+      missingIds.add(id);
+      reportHere(
+          data.compiler.reporter,
+          computeSpannable(data.elementEnvironment, data.mainUri, id),
+          'Expected $expected for id $id missing in ${data.actualMap.keys}');
+    }
   });
-  Expect.isTrue(
-      data.expectedMap.isEmpty, "Ids not found: ${data.expectedMap}.");
+  Expect.isTrue(missingIds.isEmpty, "Ids not found: ${missingIds}.");
 }
 
 /// Compute a [Spannable] from an [id] in the library [mainUri].
 Spannable computeSpannable(
     ElementEnvironment elementEnvironment, Uri mainUri, Id id) {
   if (id is NodeId) {
     return new SourceSpan(mainUri, id.value, id.value + 1);
   } else if (id is ElementId) {
     LibraryEntity library = elementEnvironment.lookupLibrary(mainUri);
     if (id.className != null) {
@@ skipping 19 matching lines @@
       id = new NodeId(annotation.offset);
       expected = text;
     } else {
       id = new ElementId(text.substring(0, colonPos));
       expected = text.substring(colonPos + 1);
     }
     map[id] = expected;
   }
   return map;
 }