fix DDC codegen test

pkg/dev_compiler/test/codegen_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.
 
 /// Tests code generation.
 ///
 /// Runs Dart Dev Compiler on all input in the `codegen` directory and checks
 /// that the output is what we expected.
 library dev_compiler.test.codegen_test;
 
@@ skipping 121 matching lines @@
       var contents = new File(testFile).readAsStringSync();
       var match = testFileOptionsMatcher.firstMatch(contents);
 
       var args = defaultOptions.toList();
       if (match != null) {
         var matchedArgs = match.group(2).split(' ');
         args.addAll(matchedArgs.where((s) => !ignoreOptions.contains(s)));
       }
 
       var declaredVars = <String, String>{};
-      var argResults =
-          compileArgParser.parse(extractDefinedVariables(args, declaredVars));
+      args = args.expand((String arg) => arg.split('=')).toList();
+      args = extractDefinedVariables(args, declaredVars);
+      ArgResults argResults;
+      try {
+        argResults = compileArgParser.parse(args);
+      } catch (e) {
+        print('Failed to parse $args');
+        rethrow;
+      }
       var options = new CompilerOptions.fromArguments(argResults);
       var moduleFormat = parseModuleFormatOption(argResults).first;
 
       // Collect any other files we've imported.
       var files = new Set<String>();
       _collectTransitiveImports(contents, files, from: testFile);
       var unit = new BuildUnit(
           name, path.dirname(testFile), files.toList(), _moduleForLibrary);
 
       var compiler = sharedCompiler;
@@ skipping 203 matching lines @@
   StringLiteral uriLiteral = directive.uri;
   String uriContent = uriLiteral.stringValue;
   if (uriContent != null) {
     uriContent = uriContent.trim();
     directive.uriContent = uriContent;
   }
   return (directive as UriBasedDirectiveImpl).validate() == null
       ? uriContent
       : null;
 }