housecleaning: remove nonnullableTypes

lib/src/info.dart

 // Copyright (c) 2015, 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.
 
 /// Defines static information collected by the type checker and used later by
 /// emitters to generate code.
 library dev_compiler.src.info;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
@@ skipping 204 matching lines @@
     final fromT = cast.fromType;
     final toT = cast.toType;
 
     // toT <:_R fromT => to <: fromT
     // NB: classes with call methods are subtypes of function
     // types, but the function type is not assignable to the class
     assert(toT.isSubtypeOf(fromT) || fromT.isAssignableTo(toT));
 
     // Handle null call specially.
     if (expression is NullLiteral) {
-      if (rules.isNonNullableType(toT)) {
-        reason = "null is invalid as a $toT";
-        return new StaticTypeError(rules, expression, toT, reason: reason);
-      } else {
-        // We should only get here if some coercion is required.
-        assert(rules.maybeNonNullableType(toT));
-        // TODO(vsm): Create a NullCast for this once we revisit nonnullability.
-        return new DownCastImplicit(rules, expression, cast);
-      }
+      // TODO(vsm): Create a NullCast for this once we revisit nonnullability.
+      return new DownCastImplicit(rules, expression, cast);
     }
 
     // Inference "casts":
     if (expression is Literal) {
       // fromT should be an exact type - this will almost certainly fail at
       // runtime.
       return new StaticTypeError(rules, expression, toT, reason: reason);
     }
     if (expression is FunctionExpression) {
       // fromT should be an exact type - this will almost certainly fail at
@@ skipping 329 matching lines @@
 /// Better to have `super` at the end, as required by the Dart style guide:
 /// <http://goo.gl/q1T4BB>
 ///
 /// For now this is the only pattern we support.
 class InvalidSuperInvocation extends StaticError {
   InvalidSuperInvocation(SuperConstructorInvocation node) : super(node);
 
   @override String get message => "super call must be last in an initializer "
       "list (see http://goo.gl/q1T4BB): {0}";
 }