Add FunctionEntity.asyncMarker and refactor SourceInformationStrategy to avoid ResolvedAst

pkg/compiler/lib/src/kernel/elements.dart

 // Copyright (c) 2017, 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.
 
 /// Entity model for elements derived from Kernel IR.
 
 import '../elements/entities.dart';
 import '../elements/names.dart';
 import '../elements/types.dart';
 
@@ skipping 74 matching lines @@
 
   String get _kind;
 
   String toString() =>
       '$_kind(${enclosingClass != null ? '${enclosingClass.name}.' : ''}$name)';
 }
 
 abstract class KFunction extends KMember implements FunctionEntity {
   final ParameterStructure parameterStructure;
   final bool isExternal;
+  final AsyncMarker asyncMarker;
 
   KFunction(int memberIndex, KLibrary library, KClass enclosingClass, Name name,
-      this.parameterStructure,
+      this.parameterStructure, this.asyncMarker,
       {bool isStatic: false, this.isExternal: false})
       : super(memberIndex, library, enclosingClass, name, isStatic: isStatic);
 }
 
 abstract class KConstructor extends KFunction implements ConstructorEntity {
   final bool isConst;
 
   KConstructor(int memberIndex, KClass enclosingClass, Name name,
       ParameterStructure parameterStructure, {bool isExternal, this.isConst})
       : super(memberIndex, enclosingClass.library, enclosingClass, name,
-            parameterStructure,
+            parameterStructure, AsyncMarker.SYNC,
             isExternal: isExternal);
 
   @override
   bool get isConstructor => true;
 
   @override
   bool get isInstanceMember => false;
 
   @override
   bool get isStatic => false;
@@ skipping 27 matching lines @@
   bool get isFactoryConstructor => true;
 
   @override
   bool get isGenerativeConstructor => false;
 }
 
 class KMethod extends KFunction {
   final bool isAbstract;
 
   KMethod(int memberIndex, KLibrary library, KClass enclosingClass, Name name,
-      ParameterStructure parameterStructure,
+      ParameterStructure parameterStructure, AsyncMarker asyncMarker,
       {bool isStatic, bool isExternal, this.isAbstract})
       : super(memberIndex, library, enclosingClass, name, parameterStructure,
+            asyncMarker,
             isStatic: isStatic, isExternal: isExternal);
 
   @override
   bool get isFunction => true;
 
   String get _kind => 'method';
 }
 
 class KGetter extends KFunction {
   final bool isAbstract;
 
   KGetter(int memberIndex, KLibrary library, KClass enclosingClass, Name name,
+      AsyncMarker asyncMarker,
       {bool isStatic, bool isExternal, this.isAbstract})
       : super(memberIndex, library, enclosingClass, name,
-            const ParameterStructure.getter(),
+            const ParameterStructure.getter(), asyncMarker,
             isStatic: isStatic, isExternal: isExternal);
 
   @override
   bool get isGetter => true;
 
   String get _kind => 'getter';
 }
 
 class KSetter extends KFunction {
   final bool isAbstract;
 
   KSetter(int memberIndex, KLibrary library, KClass enclosingClass, Name name,
       {bool isStatic, bool isExternal, this.isAbstract})
       : super(memberIndex, library, enclosingClass, name,
-            const ParameterStructure.setter(),
+            const ParameterStructure.setter(), AsyncMarker.SYNC,
             isStatic: isStatic, isExternal: isExternal);
 
   @override
   bool get isAssignable => true;
 
   @override
   bool get isSetter => true;
 
   String get _kind => 'setter';
 }
@@ skipping 27 matching lines @@
   final MemberEntity memberContext;
   final Entity executableContext;
   final FunctionType functionType;
 
   KLocalFunction(
       this.name, this.memberContext, this.executableContext, this.functionType);
 
   String toString() =>
       'local_function(${memberContext.name}.${name ?? '<anonymous>'})';
 }