Check for compile-time constants in DartCompiler

tests/language/src/StringInterpolation7NegativeTest.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.
+//
+// Disallow assignment of string interpolation to a static final field
 
-class Other1 {
-  // The existence of this final triggers b/5078969.
-  static final Function FN = () { return 42; };
+class A {
+  static final x = 1;
+  static final y = "Two is greater than ${x}";  // ERROR: String interpolation 
+}
 
-  Other1() { }
-}
+main() {
+}