dart2js: Fix hints in code base.

pkg/compiler/lib/src/tree_ir/tree_ir_builder.dart

 // Copyright (c) 2014, 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.
 
 library tree_ir_builder;
 
 import '../dart2jslib.dart' as dart2js;
-import '../dart_types.dart';
 import '../elements/elements.dart';
 import '../cps_ir/cps_ir_nodes.dart' as cps_ir;
 import '../util/util.dart' show CURRENT_ELEMENT_SPANNABLE;
 import 'tree_ir_nodes.dart';
 
 /**
  * Builder translates from CPS-based IR to direct-style Tree.
  *
  * A call `Invoke(fun, cont, args)`, where cont is a singly-referenced
  * non-exit continuation `Cont(v, body)` is translated into a direct-style call
@@ skipping 359 matching lines @@
 
   Statement visitRethrow(cps_ir.Rethrow node) {
     return new Rethrow();
   }
 
   Statement visitUnreachable(cps_ir.Unreachable node) {
     return new Unreachable();
   }
 
   Expression visitNonTailThrow(cps_ir.NonTailThrow node) {
-    unexpectedNode(node);
+    return unexpectedNode(node);
   }
 
   Statement continueWithExpression(cps_ir.Reference continuation,
                                    Expression expression) {
     cps_ir.Continuation cont = continuation.definition;
     if (cont == returnContinuation) {
       return new Return(expression);
     } else {
       assert(cont.parameters.length == 1);
       Function nextBuilder = cont.hasExactlyOneUse ?
@@ skipping 120 matching lines @@
         })
     );
   }
 
   FunctionDefinition makeSubFunction(cps_ir.FunctionDefinition function) {
     return createInnerBuilder().buildFunction(function);
   }
 
   Expression visitCreateFunction(cps_ir.CreateFunction node) {
     FunctionDefinition def = makeSubFunction(node.definition);
-    FunctionType type = node.definition.element.type;
-    bool hasReturnType = !type.returnType.treatAsDynamic;
     return new FunctionExpression(def);
   }
 
   visitParameter(cps_ir.Parameter node) {
     // Continuation parameters are not visited (continuations themselves are
     // not visited yet).
     unexpectedNode(node);
   }
 
   visitContinuation(cps_ir.Continuation node) {
@@ skipping 40 matching lines @@
 
   Statement visitSetStatic(cps_ir.SetStatic node) {
     SetStatic setStatic = new SetStatic(
         node.element,
         getVariableUse(node.value),
         node.sourceInformation);
     return new ExpressionStatement(setStatic, visit(node.body));
   }
 }