Rewrite negative const tests into a few multi tests.

tests/language/src/ConstInit5NegativeTest.dart

Index: tests/language/src/ConstInit5NegativeTest.dart
diff --git a/tests/language/src/ConstInit5NegativeTest.dart b/tests/language/src/ConstInit5NegativeTest.dart
deleted file mode 100644
index f0b121ce711a2c0afeb9f9a1c31e1e923ba076d5..0000000000000000000000000000000000000000
--- a/tests/language/src/ConstInit5NegativeTest.dart
+++ /dev/null
@@ -1,17 +0,0 @@
-// 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.
-// Check for proper types used in compile time constant expressions
-
-final A = 1;
-final B = "Hello";
-final C = A + B; // error: sub-expressions of binary + must be numeric
-
-int main() {
-  try {
-    // Some Dart implementations may not check C until it is about to be executed
-    print(C);
-  } catch (Exception e) {
-    // should be a compilation error, not a catchable exception
-  }
-}