Typing fixes to eliminate casts/dcalls

test/dart_codegen/expect/async/stream_pipe.dart

Index: test/dart_codegen/expect/async/stream_pipe.dart
diff --git a/test/dart_codegen/expect/async/stream_pipe.dart b/test/dart_codegen/expect/async/stream_pipe.dart
index 8bc784664c5f08037f4e498a6ec4392de808e65f..081ecf9423efe50aeb1c4d1d602d252504e5aa26 100644
--- a/test/dart_codegen/expect/async/stream_pipe.dart
+++ b/test/dart_codegen/expect/async/stream_pipe.dart
@@ -130,7 +130,7 @@ sink._add(inputEvent);
  void _handleData(S inputEvent, _EventSink<T> sink) {
 T outputEvent;
  try {
-outputEvent = ((__x63) => DEVC$RT.cast(__x63, dynamic, T, "CompositeCast", """line 235, column 21 of dart:async/stream_pipe.dart: """, __x63 is T, false))(_transform(inputEvent));
+outputEvent = ((__x58) => DEVC$RT.cast(__x58, dynamic, T, "CompositeCast", """line 235, column 21 of dart:async/stream_pipe.dart: """, __x58 is T, false))(_transform(inputEvent));
 }
  catch (e, s) {
 _addErrorWithReplacement(sink, e, s);