Merge two static_final_field tests and rewrite a negative test to a multi-test

tests/language/throw7_negative_test.dart

-// Copyright (c) 2011, 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.
-// Dart test program for testing throw statement
-
-class MyException1 {
-  const MyException1([String message = "1"]) : message_ = message;
-  final String message_;
-}
-
-class Helper {
-  Helper() : i = 0 { }
-
-  int f1() {
-    int j = 0;
-    try {
-      j = i;
-    } catch (exception) {
-      i = i + 100;
-      print(exception.message_);
-    }
-    // Since there is a generic 'catch all' statement preceding this
-    // we expect to get a dead code error/warning over here.
-    on MyException1 catch (exception) {
-      i = i + 100;
-      print(exception.message_);
-    }
-    finally {
-      i = i + 1000;
-    }
-    return i;
-  }
-
-  int i;
-}
-
-class Throw7NegativeTest {
-  static testMain() {
-    new Helper().f1();
-  }
-}
-
-main() {
-  Throw7NegativeTest.testMain();
-}