Add assert-in-initializer-list to formal specification.

tests/language/assertion_initializer_const_function_error_test.dart

Index: tests/language/assertion_initializer_const_function_error_test.dart
diff --git a/tests/language/assertion_initializer_const_function_error_test.dart b/tests/language/assertion_initializer_const_function_error_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..638af0d44b343d717b633eba3bbf832c6a0363e1
--- /dev/null
+++ b/tests/language/assertion_initializer_const_function_error_test.dart
@@ -0,0 +1,26 @@
+// Copyright (c) 201, 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.
+// VMOptions=--assert_initializer
+//
+// Dart test program testing assert statements.
+
+import "package:expect/expect.dart";
+
+class C {
+  static bool staticTrue() => true;
+  final int x;
+  const C(this.x);
+  // The expression *is* a compile-time constant, but not a bool value.
+  // Static warning, assertion throws which makes it a compile-time error.
+  const C.bc02(this.x, y) : assert(staticTrue); //# 01: static type warning

[floitsch, 2017/06/29 12:08:56]

ditto: move 'assert' into a separate line.

+}
+
+
+main() {
+  var c = const C(1);
+  // Assertion fails, so in checked mode it's a compile-time error.
+  // Production mode will succeed because the assertion isn't evaluated.
+  c = const C.bc02(1, 2);  //# 01: compile-time error
+  if (c.x != 1) throw "non-trivial use of c";
+}