[ffigen] Switch to named params for ObjC methods

[liamappelbe]

Change the way ObjC methods are generated to use named params, similarly to how ObjC works. Eg dataWithBytes_length_(Pointer<Void> bytes, int length), is now generated as dataWithBytes(Pointer<Void> bytes, {required int length}). This is generally much more readable, but does lead to more method renamings, since the shorter methods names are more likely to collide.

If the named parameter is nullable, it's generated as optional. Protocol method generation hasn't been changed, and are still generated using the long names.

I'll publish ffigen 19 once this lands.

Fixes #1566

[github-actions]

PR Health

Breaking changes ✔️

Package	Change	Current Version	New Version	Needed Version	Looking good?
objective_c	Breaking	7.1.0	8.0.0	8.0.0	✔️

Changelog Entry ✔️

Package	Changed Files

Changes to files need to be accounted for in their respective changelogs.

API leaks ⚠️

The following packages contain symbols visible in the public API, but not exported by the library. Export these symbols or remove them from your publicly visible API.

Package	Leaked API symbols
objective_c	_Version

This check can be disabled by tagging the PR with skip-leaking-check.

License Headers ⚠️

// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

Files
pkgs/objective_c/lib/src/ns_input_stream.dart

All source files should start with a license header.

Unrelated files missing license headers

Files
pkgs/jni/lib/src/third_party/generated_bindings.dart

This check can be disabled by tagging the PR with skip-license-check.

[coveralls]

coverage: 91.735% (+0.04%) from 91.694%
when pulling e4d482a on namedparams
into 5c7152e on main.