Allow S->T <: dynamic->T

test/dart_codegen/expect/convert/json.dart

 part of dart.convert;
  class JsonUnsupportedObjectError extends Error {final unsupportedObject;
  final cause;
  JsonUnsupportedObjectError(this.unsupportedObject, {
   this.cause}
 );
  String toString() {
   if (cause != null) {
     return "Converting object to an encodable object failed.";
     }
@@ skipping 330 matching lines @@
  for (int i = 1; i < list.length; i++) {
 writeString(',');
  writeObject(list[i]);
 }
 }
  writeString(']');
 }
  void writeMap(Map<String, Object> map) {
 writeString('{');
  String separator = '"';
- map.forEach((String key, value) {
+ map.forEach(((__x27) => DEVC$RT.wrap((dynamic f(String __u19, dynamic __u20)) {
+dynamic c(String x0, dynamic x1) => f(x0, x1);
+ return f == null ? null : c;
+}
+, __x27, __t24, __t21, "WrapLiteral", """line 721, column 17 of dart:convert/json.dart: """, __x27 is __t21))((String key, value) {
 writeString(separator);
  separator = ',"';
  writeStringContent(key);
  writeString('":');
  writeObject(value);
 }
-);
+));
  writeString('}');
 }
 }
  abstract class _JsonPrettyPrintMixin implements _JsonStringifier {int _indentLevel = 0;
  void writeIndentation(indentLevel);
  void writeList(List list) {
 if (list.isEmpty) {
 writeString('[]');
 }
  else {
@@ skipping 13 matching lines @@
 }
 }
  void writeMap(Map map) {
 if (map.isEmpty) {
 writeString('{}');
 }
  else {
 writeString('{\n');
  _indentLevel++;
  bool first = true;
- map.forEach(((__x27) => DEVC$RT.wrap((dynamic f(String __u19, Object __u20)) {
-dynamic c(String x0, Object x1) => f(DEVC$RT.cast(x0, dynamic, String, "CastParam", """line 773, column 19 of dart:convert/json.dart: """, x0 is String, true), x1);
- return f == null ? null : c;
-}
-, __x27, __t24, __t21, "WrapLiteral", """line 773, column 19 of dart:convert/json.dart: """, __x27 is __t21))((String key, Object value) {
+ map.forEach((String key, Object value) {
 if (!first) {
 writeString(",\n");
 }
  writeIndentation(_indentLevel);
  writeString('"');
  writeStringContent(key);
  writeString('": ');
  writeObject(value);
  first = false;
 }
-));
+);
  writeString('\n');
  _indentLevel--;
  writeIndentation(_indentLevel);
  writeString('}');
 }
 }
 }
  class _JsonStringStringifier extends _JsonStringifier {final StringSink _sink;
  _JsonStringStringifier(this._sink, _toEncodable) : super(DEVC$RT.cast(_toEncodable, dynamic, __t7, "CastGeneral", """line 798, column 60 of dart:convert/json.dart: """, _toEncodable is __t7, false));
  static String stringify(object, toEncodable(object), String indent) {
@@ skipping 141 matching lines @@
 for (int i = 0; i < indentLength; i++) {
 writeByte(indent[i]);
 }
 }
 }
 }
 }
  typedef Object __t7(Object __u8);
  typedef dynamic __t9(dynamic __u10);
  typedef dynamic __t13(Object __u14);
- typedef void __t21(dynamic __u22, dynamic __u23);
- typedef dynamic __t24(String __u25, Object __u26);
+ typedef void __t21(String __u22, Object __u23);
+ typedef dynamic __t24(String __u25, dynamic __u26);