fix #28630, instance method tear-offs are treated as strict arrows

pkg/dev_compiler/tool/sdk_expected_errors.txt

Index: pkg/dev_compiler/tool/sdk_expected_errors.txt
diff --git a/pkg/dev_compiler/tool/sdk_expected_errors.txt b/pkg/dev_compiler/tool/sdk_expected_errors.txt
index b60c5bd223d8b88919bad9adb1d968d8e7d50fcd..94a78502c1f4306c3975f9f76cb2fe994a80f8f0 100644
--- a/pkg/dev_compiler/tool/sdk_expected_errors.txt
+++ b/pkg/dev_compiler/tool/sdk_expected_errors.txt
@@ -13,7 +13,6 @@
 [error] Couldn't infer type parameter 'S'; 'RandomAccessFile' must be of type 'File'. (dart:io/file_impl.dart, line 216, col 19)
 [error] The argument type '(RandomAccessFile) → Future<RandomAccessFile>' can't be assigned to the parameter type '(RandomAccessFile) → FutureOr<File>'. (dart:io/file_impl.dart, line 216, col 24)
 [error] The return type 'Future' isn't a 'FutureOr<File>', as defined by the method ''. (dart:io/file_impl.dart, line 545, col 14)
-[error] The argument type '([dynamic]) → void' can't be assigned to the parameter type '(_ConnectionInfo) → FutureOr<void>'. (dart:io/http_impl.dart, line 1633, col 19)
 [error] The return type 'StreamSubscription<int>' isn't a 'StreamSubscription<List<int>>', as defined by the method 'listen'. (dart:io/http_parser.dart, line 208, col 14)
 [error] The argument type '(List<int>) → void' can't be assigned to the parameter type '(int) → void'. (dart:io/http_parser.dart, line 209, col 19)
 [error] Couldn't infer type parameter 'V'; 'Object' must be of type 'String'. (dart:io/io_resource_info.dart, line 27, col 7)
@@ -29,7 +28,6 @@
 [error] Couldn't infer type parameter 'V'; 'Object' must be of type 'String'. (dart:io/io_resource_info.dart, line 159, col 5)
 [error] The element type 'int' can't be assigned to the map value type 'String'. (dart:io/io_resource_info.dart, line 161, col 13)
 [error] The element type 'double' can't be assigned to the map value type 'String'. (dart:io/io_resource_info.dart, line 164, col 20)
-[error] The argument type '([dynamic]) → void' can't be assigned to the parameter type '(RawSocket) → FutureOr<void>'. (dart:io/secure_socket.dart, line 591, col 28)
 [error] The argument type 'List' can't be assigned to the parameter type 'Iterable<int>'. (dart:io/secure_socket.dart, line 1129, col 23)
 [error] Undefined name 'lineMode'. (dart:io/stdio.dart, line 64, col 10)
 [error] The name 'echoMode=' is already defined. (dart:io/stdio.dart, line 126, col 12)