Constant get and invoke are never called.

lib/kernel_visitor.dart

 // Copyright (c) 2016, 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.md file.
 
 library rasta.kernel_visitor;
 
 import 'package:kernel/ast.dart' as ir;
 
 import 'package:kernel/accessors.dart' show
     Accessor,
@@ skipping 1230 matching lines @@
 
   @override
   ir.Expression visitConstConstructorInvoke(
       NewExpression node,
       ConstructedConstantExpression constant,
       _) {
     return buildConstConstructorInvoke(node);
   }
 
   @override
-  ir.Throw visitConstantGet(Send node, ConstantExpression constant, _) {
-    return buildUnsupported(node, "ConstantGet");
+  visitConstantGet(Send node, ConstantExpression constant, _) {
+    // TODO(ahe): This method is never called. Is it a bug in semantic visitor?
+    return internalError(node, "ConstantGet");
   }
 
   @override
-  ir.Throw visitConstantInvoke(
+  visitConstantInvoke(
       Send node,
       ConstantExpression constant,
       NodeList arguments,
       CallStructure callStructure,
       _) {
-    return buildUnsupported(node, "ConstantInvoke");
+    // TODO(ahe): This method is never called. Is it a bug in semantic visitor?
+    return internalError(node, "ConstantInvoke");
   }
 
   @override
   ir.InvalidExpression visitConstructorIncompatibleInvoke(
       NewExpression node,
       ConstructorElement constructor,
       InterfaceType type,
       NodeList arguments,
       CallStructure callStructure,
       _) {
@@ skipping 1780 matching lines @@
       : this(null, true, node, initializers);
 
   accept(ir.Visitor v) => throw "unsupported";
 
   visitChildren(ir.Visitor v) => throw "unsupported";
 
   String toString() {
     return "IrFunction($kind, $isConstructor, $node, $initializers)";
   }
 }