refactor DDC to support --ignore-unrecognized-flags

pkg/analyzer/test/src/command_line/arguments_test.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 analyzer.test.src.command_line.arguments_test;
 
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/command_line/arguments.dart';
 import 'package:analyzer/src/context/builder.dart';
 import 'package:analyzer/src/dart/sdk/sdk.dart';
@@ skipping 137 matching lines @@
     args = extractDefinedVariables(args, definedVariables);
     expect(args, orderedEquals(['--a', 'back=blue', '-Dx']));
     expect(definedVariables['one'], 'two');
     expect(definedVariables['two'], isNull);
     expect(definedVariables['baz'], 'go');
     expect(definedVariables['go'], isNull);
     expect(definedVariables, hasLength(2));
   }
 
   void test_filterUnknownArguments() {
-    List<String> args = ['--a', '--b', '--c', 'foo', 'bar'];
+    List<String> args = ['--a', '--b', '--c=0', '--d=1', '-e=2', '-f', 'bar'];
     ArgParser parser = new ArgParser();
     parser.addFlag('a');
-    parser.addFlag('c');
+    parser.addOption('c');
+    parser.addOption('ee', abbr: 'e');
+    parser.addFlag('ff', abbr: 'f');
     List<String> result = filterUnknownArguments(args, parser);
-    expect(result, orderedEquals(['--a', '--c', 'foo', 'bar']));
+    expect(result, orderedEquals(['--a', '--c=0', '-e=2', '-f', 'bar']));
   }
 
   void test_parse_noReplacement_noIgnored() {
     MemoryResourceProvider provider = new MemoryResourceProvider();
     ArgParser parser = new ArgParser();
     parser.addFlag('xx');
     parser.addOption('yy');
     List<String> args = ['--xx', '--yy=abc', 'foo', 'bar'];
     ArgResults result = parse(provider, parser, args);
     expect(result, isNotNull);
@@ skipping 41 matching lines @@
   }
 
   void test_preprocessArgs_replacement_notLast() {
     MemoryResourceProvider provider = new MemoryResourceProvider();
     String filePath = provider.convertPath('/args.txt');
     List<String> args = ['a', '@$filePath', 'b'];
     List<String> result = preprocessArgs(provider, args);
     expect(result, orderedEquals(args));
   }
 }