Decouple WorkItem from Compiler

pkg/compiler/lib/src/kernel/kernel.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.
 
 import 'dart:async';
 import 'dart:collection' show Queue;
 
 import 'package:kernel/ast.dart' as ir;
 import 'package:kernel/checks.dart' show CheckParentPointers;
 
@@ skipping 390 matching lines @@
       internalError(function, "Deferred loader.");
     }
     if (function.isLocal) {
       internalError(function, "Local function.");
     }
     if (isSyntheticError(function)) {
       internalError(function, "Synthetic error function: $function.");
     }
     function = function.declaration;
     return functions.putIfAbsent(function, () {
-      compiler.analyzeElement(function);
+      compiler.resolution.ensureResolved(function);
       compiler.enqueuer.resolution.emptyDeferredQueueForTesting();
       function = function.implementation;
       ir.Member member;
       ir.Constructor constructor;
       ir.Procedure procedure;
       ir.Name name = irName(function.name, function);
       bool isNative = isNativeMethod(function);
       if (function.isGenerativeConstructor) {
         member = constructor = new ir.Constructor(null,
             name: name,
@@ skipping 77 matching lines @@
   void endFactoryScope(FunctionElement function) {
     factoryTypeParameters.clear();
   }
 
   ir.Field fieldToIr(FieldElement field) {
     if (isSyntheticError(field)) {
       internalError(field, "Synthetic error field: $field.");
     }
     field = field.declaration;
     return fields.putIfAbsent(field, () {
-      compiler.analyzeElement(field);
+      compiler.resolution.ensureResolved(field);
       compiler.enqueuer.resolution.emptyDeferredQueueForTesting();
       field = field.implementation;
       ir.DartType type =
           field.isMalformed ? const ir.InvalidType() : typeToIr(field.type);
       ir.Field fieldNode = new ir.Field(irName(field.memberName.text, field),
           type: type,
           initializer: null,
           isFinal: field.isFinal,
           isStatic: field.isStatic || field.isTopLevel,
           isConst: field.isConst);
@@ skipping 234 matching lines @@
 }
 
 class ConstructorTarget {
   final ConstructorElement element;
   final DartType type;
 
   ConstructorTarget(this.element, this.type);
 
   String toString() => "ConstructorTarget($element, $type)";
 }