Do not error on dead, mandated statements at end of switch cases

pkg/analyzer/test/generated/non_hint_code_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.generated.non_hint_code_test;
 
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 
 import '../reflective_tests.dart';
@@ skipping 172 matching lines @@
   if (1 < 0) {
     return;
   }
   int a = 1;
 }''');
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
     verify([source]);
   }
 
+  void test_deadCode_deadFinalBreakInCase() {
+    Source source = addSource(r'''
+f() {
+  switch (true) {
+  case true:
+    try {
+      int a = 1;
+    } finally {
+      return;
+    }
+    break;

[Paul Berry, 2016/06/14 18:39:27]

Please also add tests for the other kind of statements you're checking for
(continue, return, throw).

(Assuming you take my previous suggestion and make those statements generate
hints, then the additional tests should of course go in hint_code_test.dart).

[srawlins, 2016/06/14 21:09:55]

Acknowledged.

+  default:
+    break;
+  }
+}''');
+    computeLibrarySourceErrors(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
   void test_deprecatedMemberUse_inDeprecatedClass() {
     Source source = addSource(r'''
 @deprecated
 f() {}
 
 @deprecated
 class C {
   m() {
     f();
   }
@@ skipping 1055 matching lines @@
 
   void test_import_valid_outside_lib() {
     cacheSource("/myproj/pubspec.yaml", "");
     cacheSource("/myproj/web/other.dart", "");
     Source source =
         addNamedSource("/myproj/lib2/test.dart", "import '../web/other.dart';");
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
   }
 }