Add ConstructorBodyEntity

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

Index: pkg/compiler/lib/src/kernel/kelements.dart
diff --git a/pkg/compiler/lib/src/kernel/kelements.dart b/pkg/compiler/lib/src/kernel/kelements.dart
index 8d968e4b06803a26979c6852ea87e4532bd57381..bba1b739f6134785effc08375c9c8b7267f3842b 100644
--- a/pkg/compiler/lib/src/kernel/kelements.dart
+++ b/pkg/compiler/lib/src/kernel/kelements.dart
@@ -164,6 +164,26 @@ class KFactoryConstructor extends KConstructor {
   bool get isGenerativeConstructor => false;
 }
 
+class KConstructorBody extends KFunction implements ConstructorBodyEntity {
+  final ConstructorEntity constructor;
+
+  KConstructorBody(int memberIndex, this.constructor)
+      : super(
+            memberIndex,
+            constructor.library,
+            constructor.enclosingClass,
+            constructor.memberName,
+            constructor.parameterStructure,
+            AsyncMarker.SYNC,
+            isStatic: false,
+            isExternal: false);
+
+  @override
+  bool get isFunction => true;
+
+  String get _kind => 'constructor_body';
+}
+
 class KMethod extends KFunction {
   final bool isAbstract;