Add FunctionEntity.asyncMarker and refactor SourceInformationStrategy to avoid ResolvedAst

pkg/compiler/lib/src/kernel/element_map_impl.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.
 
 library dart2js.kernel.element_map;
 
 import 'package:kernel/ast.dart' as ir;
 import 'package:kernel/clone.dart';
 import 'package:kernel/type_algebra.dart';
 
@@ skipping 281 matching lines @@
         enclosingClass = _getClass(node.enclosingClass);
         library = enclosingClass.library;
       } else {
         library = _getLibrary(node.enclosingLibrary);
       }
       Name name = getName(node.name);
       bool isStatic = node.isStatic;
       bool isExternal = node.isExternal;
       bool isAbstract = node.isAbstract;
       KFunction function;
+      AsyncMarker asyncMarker;
+      switch (node.function.asyncMarker) {
+        case ir.AsyncMarker.Async:
+          asyncMarker = AsyncMarker.ASYNC;
+          break;
+        case ir.AsyncMarker.AsyncStar:
+          asyncMarker = AsyncMarker.ASYNC_STAR;
+          break;
+        case ir.AsyncMarker.Sync:
+          asyncMarker = AsyncMarker.SYNC;
+          break;
+        case ir.AsyncMarker.SyncStar:
+          asyncMarker = AsyncMarker.SYNC_STAR;
+          break;
+        case ir.AsyncMarker.SyncYielding:
+          throw new UnsupportedError(
+              "Async marker ${node.function.asyncMarker} is not supported.");
+      }
       switch (node.kind) {
         case ir.ProcedureKind.Factory:
           throw new UnsupportedError("Cannot create method from factory.");
         case ir.ProcedureKind.Getter:
-          function = new KGetter(memberIndex, library, enclosingClass, name,
+          function = new KGetter(
+              memberIndex, library, enclosingClass, name, asyncMarker,
               isStatic: isStatic,
               isExternal: isExternal,
               isAbstract: isAbstract);
           break;
         case ir.ProcedureKind.Method:
         case ir.ProcedureKind.Operator:
           function = new KMethod(memberIndex, library, enclosingClass, name,
-              _getParameterStructure(node.function),
+              _getParameterStructure(node.function), asyncMarker,
               isStatic: isStatic,
               isExternal: isExternal,
               isAbstract: isAbstract);
           break;
         case ir.ProcedureKind.Setter:
+          assert(asyncMarker == AsyncMarker.SYNC);
           function = new KSetter(
               memberIndex, library, enclosingClass, getName(node.name).setter,
               isStatic: isStatic,
               isExternal: isExternal,
               isAbstract: isAbstract);
           break;
       }
       _memberList.add(new _FunctionData(node, node.function));
       return function;
     });
@@ skipping 1182 matching lines @@
     return node.isExternal &&
         !elementMap.isForeignLibrary(node.enclosingLibrary);
   }
 
   @override
   bool isJsInteropMember(MemberEntity element) {
     // TODO(johnniwinther): Compute this.
     return false;
   }
 }