When reordering constructor initializers, use correct types for temp vars.

pkg/front_end/testcases/reorder_super.dart.outline.expect

Index: pkg/front_end/testcases/reorder_super.dart.outline.expect
diff --git a/pkg/front_end/testcases/reorder_super.dart.outline.expect b/pkg/front_end/testcases/reorder_super.dart.outline.expect
new file mode 100644
index 0000000000000000000000000000000000000000..947f8d25c606258a50f58c5b073e76a99645eb1a
--- /dev/null
+++ b/pkg/front_end/testcases/reorder_super.dart.outline.expect
@@ -0,0 +1,22 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class B extends core::Object {
+  field core::num x;
+  field core::String y;
+  constructor •(core::num x, core::String y) → void
+    ;
+}
+class C extends self::B {
+  final field dynamic z;
+  constructor •() → void
+    ;
+}
+static field core::String events;
+static method f(dynamic x) → core::int
+  ;
+static method g(dynamic x) → core::String
+  ;
+static method main() → dynamic
+  ;