Set MethodInvocation.interfaceTarget during type inference.

pkg/front_end/lib/src/fasta/testing/validating_instrumentation.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.md file.
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:front_end/src/base/instrumentation.dart';
 import 'package:front_end/src/fasta/messages.dart';
 import 'package:front_end/src/fasta/scanner.dart';
 import 'package:front_end/src/fasta/scanner/io.dart';
 import 'package:front_end/src/scanner/token.dart' as analyzer;
 
 /// Implementation of [Instrumentation] which checks property/value pairs
 /// against expectations encoded in source files using "/*@...*/" comments.
 class ValidatingInstrumentation implements Instrumentation {
   static final _ESCAPE_SEQUENCE = new RegExp(r'\\(.)');
 
   /// Map from feature names to the property names they are short for.
   static const _FEATURES = const {
     'inference': const [
       'topType',
       'typeArg',
       'typeArgs',
       'promotedType',
       'type',
-      'returnType'
+      'returnType',
+      'target',
     ],
   };
 
   /// Map from file URI to the as-yet unsatisfied expectations from that file,
   /// organized by file offset.
   final _unsatisfiedExpectations = <Uri, Map<int, List<_Expectation>>>{};
 
   /// Information about "testedFeatures" annotations, organized by file URI and
   /// file offset.  The inner map is guaranteed to be in ascending order of
   /// file offset.
@@ skipping 131 matching lines @@
     if (_shouldCheck(property, uri, offset)) {
       _problemWithStack(
           uri,
           offset,
           'expected nothing, got $property=${value.toString()}',
           new _Fix(offset, 0, _makeExpectationComment(property, value)));
     }
   }
 
   String _escape(String s) {
-    return s.replaceAll(r'\', r'\\').replaceAll('*/', r'*\/');
+    s = s.replaceAll(r'\', r'\\');
+    if (s.endsWith('/')) {
+      s = '$s ';
+    }
+    return s.replaceAll('/*', r'/\*').replaceAll('*/', r'*\/');
   }
 
   String _formatProblem(
       Uri uri, int offset, String desc, StackTrace stackTrace) {
     return format(
         uri, offset, '$desc${stackTrace == null ? '' : '\n$stackTrace'}');
   }
 
   String _makeExpectationComment(String property, InstrumentationValue value) {
     return '/*@$property=${_escape(value.toString())}*/';
@@ skipping 32 matching lines @@
       this.property, this.value, this.commentOffset, this.commentLength);
 }
 
 class _Fix {
   final int offset;
   final int length;
   final String replacement;
 
   _Fix(this.offset, this.length, this.replacement);
 }