Bugfixes in CPS RecursiveVisitor and ParentVisitor.

pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart

Index: pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
index 3296adc2b91ef0b3ac150666749ec9a496c09520..c1cb9700b4a7fd4cde99306c5ee0d7f5d5d9cb45 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
@@ -983,14 +983,13 @@ abstract class RecursiveVisitor extends Visitor {
   processFieldInitializer(FieldInitializer node) {}
   visitFieldInitializer(FieldInitializer node) {
     processFieldInitializer(node);
-    visit(node.body.body);
+    visit(node.body);
   }
 
   processSuperInitializer(SuperInitializer node) {}
   visitSuperInitializer(SuperInitializer node) {
     processSuperInitializer(node);
-    node.arguments.forEach(
-        (RunnableBody argument) => visit(argument.body));
+    node.arguments.forEach(visit);
   }
 
   // Expressions.
@@ -1139,6 +1138,7 @@ abstract class RecursiveVisitor extends Visitor {
   processGetMutableVariable(GetMutableVariable node) {}
   visitGetMutableVariable(GetMutableVariable node) {
     processGetMutableVariable(node);
+    processReference(node.variable);
   }
 
   processParameter(Parameter node) {}