Use precomputed constant for determining if static is lazy-init

pkg/compiler/lib/src/ssa/kernel_ast_adapter.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 file.
 
 import 'package:js_runtime/shared/embedded_names.dart';
 import 'package:kernel/ast.dart' as ir;
 
 import '../constants/expressions.dart';
 import '../common.dart';
 import '../common/names.dart';
@@ skipping 74 matching lines @@
     Element result = _nodeToElement[node];
     assert(invariant(CURRENT_ELEMENT_SPANNABLE, result != null,
         message: "No element found for $node."));
     return result;
   }
 
   MemberElement getMember(ir.Node node) => getElement(node).declaration;
 
   MethodElement getMethod(ir.Node node) => getElement(node).declaration;
 
+  FieldElement getField(ir.Node node) => getElement(node).declaration;
+
   ClassElement getClass(ir.Node node) => getElement(node).declaration;
 
   ast.Node getNode(ir.Node node) {
     ast.Node result = _nodeToAst[node];
     assert(invariant(CURRENT_ELEMENT_SPANNABLE, result != null,
         message: "No node found for $node"));
     return result;
   }
 
   Local getLocal(ir.VariableDeclaration variable) {
@@ skipping 174 matching lines @@
 
   bool isIntercepted(ir.Node node) {
     Selector selector = getSelector(node);
     return _backend.isInterceptedSelector(selector);
   }
 
   bool isInterceptedSelector(Selector selector) {
     return _backend.isInterceptedSelector(selector);
   }
 
+  // Is the member a lazy initialized static or top-level member?
+  bool isLazyStatic(ir.Member member) {
+    if (member is ir.Field) {
+      FieldElement field = _nodeToElement[member];
+      return field.constant == null;
+    }
+    return false;
+  }
+
   LibraryElement get jsHelperLibrary => _backend.helpers.jsHelperLibrary;
 
   JumpTarget getTargetDefinition(ir.Node node) =>
       elements.getTargetDefinition(getNode(node));
 
   ir.Class get mapLiteralClass =>
       kernel.classes[_backend.helpers.mapLiteralClass];
 
   ir.Procedure get mapLiteralConstructor =>
       kernel.functions[_backend.helpers.mapLiteralConstructor];
@@ skipping 465 matching lines @@
     astAdapter.reporter.internalError(
         CURRENT_ELEMENT_SPANNABLE, "Unexpected constant target: $element.");
     return null;
   }
 
   @override
   ConstantExpression visitStringLiteral(ir.StringLiteral node) {
     return new StringConstantExpression(node.value);
   }
 }