More dart2js strong mode cleanup.

pkg/front_end/test/fasta/testing.json

 {
 "":"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.md file.",
 
   "packages": "../../../../.packages",
 
   "suites": [
 
     {
@@ skipping 197 matching lines @@
     "git grep": {
       "pathspecs": [ "*.dart" ],
       "patterns": [
         "package:front_end/",
         "package:kernel/"
       ]
     },
 
     "exclude": [
       "^pkg/analysis_server/lib/src/analysis_server\\.dart",
-      "^pkg/compiler/lib/src/closure\\.dart",
-      "^pkg/compiler/lib/src/elements/elements\\.dart",
-      "^pkg/compiler/lib/src/elements/modelx\\.dart",
-      "^pkg/compiler/lib/src/inferrer/inferrer_engine\\.dart",
-      "^pkg/compiler/lib/src/js_backend/namer\\.dart",
-      "^pkg/compiler/lib/src/kernel/kernel_visitor\\.dart",
-      "^pkg/compiler/lib/src/resolution/members\\.dart",
-      "^pkg/compiler/lib/src/resolution/resolution\\.dart",
-      "^pkg/compiler/lib/src/resolution/resolution_strategy\\.dart",
-      "^pkg/compiler/lib/src/serialization/equivalence\\.dart",
-      "^pkg/compiler/lib/src/serialization/resolved_ast_serialization\\.dart",
-      "^pkg/compiler/lib/src/ssa/builder_kernel\\.dart",
       "^tests/compiler/dart2js/inference/enumerator\\.dart",
       "^tests/compiler/dart2js/inference/id_equivalence_test\\.dart",
       "^tests/compiler/dart2js/kernel/class_hierarchy_test\\.dart",
       "^tests/compiler/dart2js/kernel/impact_test\\.dart",
       "^tests/compiler/dart2js/kernel/visitor_test\\.dart",
       "^tests/compiler/dart2js/location_collector_test\\.dart",
       "^tests/compiler/dart2js/source_map_validator_helper\\.dart",
       "^tests/compiler/dart2js/sourcemaps/sourcemap_helper\\.dart"
     ]
   }
 }