Revert "Update third_party/pkg/kernel version"

pkg/compiler/lib/src/kernel/unresolved.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 'package:kernel/ast.dart' as ir;
 
 import "../dart_types.dart" show DartType, InterfaceType;
 import "../elements/elements.dart"
     show
         AstElement,
@@ skipping 254 matching lines @@
     var accessor = new ClassStaticAccessor(
         this, getter.name, possiblyErroneousFunctionToIr(getter), null);
     return accessor.buildPrefixIncrement(new ir.Name(operator.selectorName),
         voidContext: isVoidContext);
   }
 
   ir.Expression visitUnresolvedStaticSetterSetIfNull(
       Send node, MethodElement getter, Element element, Node rhs, _) {
     var accessor = new ClassStaticAccessor(
         this, getter.name, possiblyErroneousFunctionToIr(getter), null);
-    return accessor.buildNullAwareAssignment(visitForValue(rhs), null,
+    return accessor.buildNullAwareAssignment(visitForValue(rhs),
         voidContext: isVoidContext);
   }
 
   ir.Expression visitUnresolvedSuperBinary(
       Send node, Element element, BinaryOperator operator, Node argument, _) {
     return buildThrowNoSuchMethodError(
         kernel.getUnresolvedSuperMethodBuilder(),
         new ir.ThisExpression(),
         operator.selectorName,
         new ir.Arguments(<ir.Expression>[visitForValue(argument)]));
@@ skipping 164 matching lines @@
 
   ir.Expression visitUnresolvedSuperSetterPrefix(Send node,
       MethodElement getter, Element element, IncDecOperator operator, _) {
     return buildUnresolvedSuperPropertyAccessor('${node.selector}', getter)
         .buildPrefixIncrement(new ir.Name(operator.selectorName));
   }
 
   ir.Expression visitUnresolvedSuperSetterSetIfNull(
       Send node, MethodElement getter, Element element, Node rhs, _) {
     return buildUnresolvedSuperPropertyAccessor('${node.selector}', getter)
-        .buildNullAwareAssignment(visitForValue(rhs), null);
+        .buildNullAwareAssignment(visitForValue(rhs));
   }
 
   ir.Expression visitUnresolvedSuperUnary(
       Send node, UnaryOperator operator, Element element, _) {
     // TODO(asgerf): Should really call 'super.noSuchMethod'.
     return buildThrowNoSuchMethodError(
         kernel.getUnresolvedSuperMethodBuilder(),
         new ir.ThisExpression(),
         operator.selectorName,
         new ir.Arguments.empty());
@@ skipping 55 matching lines @@
     var accessor = new TopLevelStaticAccessor(
         this, getter.name, possiblyErroneousFunctionToIr(getter), null);
     return accessor.buildPrefixIncrement(new ir.Name(operator.selectorName),
         voidContext: isVoidContext);
   }
 
   ir.Expression visitUnresolvedTopLevelSetterSetIfNull(
       Send node, MethodElement getter, Element element, Node rhs, _) {
     var accessor = new TopLevelStaticAccessor(
         this, getter.name, possiblyErroneousFunctionToIr(getter), null);
-    return accessor.buildNullAwareAssignment(visitForValue(rhs), null,
+    return accessor.buildNullAwareAssignment(visitForValue(rhs),
         voidContext: isVoidContext);
   }
 
   ir.Expression visitUnresolvedSuperGetterIndexSetIfNull(Send node,
       Element element, MethodElement setter, Node index, Node rhs, _) {
     return buildUnresolvedSuperIndexAccessor(index, element)
-        .buildNullAwareAssignment(visitForValue(rhs), null);
+        .buildNullAwareAssignment(visitForValue(rhs));
   }
 
   ir.Expression visitUnresolvedSuperSetterIndexSetIfNull(Send node,
       MethodElement getter, Element element, Node index, Node rhs, _) {
     return buildUnresolvedSuperIndexAccessor(index, element)
-        .buildNullAwareAssignment(visitForValue(rhs), null);
+        .buildNullAwareAssignment(visitForValue(rhs));
   }
 
   ir.Expression visitUnresolvedSuperIndexSetIfNull(
       Send node, Element element, Node index, Node rhs, _) {
     return buildUnresolvedSuperIndexAccessor(index, element)
-        .buildNullAwareAssignment(visitForValue(rhs), null);
+        .buildNullAwareAssignment(visitForValue(rhs));
   }
 
   ir.Expression visitUnresolvedSuperSet(
       Send node, Element element, Node rhs, _) {
     return buildThrowUnresolvedSuperSetter(
         '${node.selector}', visitForValue(rhs));
   }
 }