WIP: [objective_c] Migrate to native assets

[liamappelbe]

Notes

• I'm using on @Native annotations to load all the ffi symbols. Previously this worked because I loaded the dylib into the executable first, then relied on the @Native fallback behavior to load the symbols from the exe. Now I'm explicitly setting the asset name to the built dylib. But all the core ObjC runtime symbols (eg objc_msgSend) are linked into the exe, not the dylib. So I had to split the C bindings. There are now 3 sets of ffigen created bindings: the objective C bindings, the bindings for my C code, and the bindings for the built in C code.
• ffigen has a dev dep on package:objective_c for testing. All the ObjC tests are disabled on linux and windows, but afaik there's no way of avoiding pulling in the dependency on those platforms. So I had to modify package:objective_c's build script to no-op on those platforms. Seems like a sub-optimal solution.

[github-actions]

PR Health

Changelog Entry ❗

Package

Changed Files

package:objective_c

pkgs/objective_c/example/README.md pkgs/objective_c/example/ios/Runner/Assets.xcassets/LaunchImage.imageset/README.md pkgs/objective_c/example/pubspec.yaml pkgs/objective_c/lib/objective_c.dart pkgs/objective_c/lib/src/c_bindings_generated.dart pkgs/objective_c/lib/src/internal.dart pkgs/objective_c/lib/src/objective_c_bindings_generated.dart pkgs/objective_c/lib/src/objective_c_native_base.dart pkgs/objective_c/lib/src/protocol_builder.dart pkgs/objective_c/lib/src/runtime_bindings_generated.dart pkgs/objective_c/lib/src/selector.dart pkgs/objective_c/pubspec.yaml

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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/example/lib/main.dart
pkgs/objective_c/lib/src/objective_c_native_base.dart

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Unrelated files missing license headers

Files
pkgs/jni/lib/src/third_party/generated_bindings.dart
pkgs/native_doc_dartifier/example/native_doc_dartifier_example.dart
pkgs/native_doc_dartifier/lib/native_doc_dartifier.dart
pkgs/native_doc_dartifier/lib/src/native_doc_dartifier_base.dart
pkgs/objective_c/lib/src/ns_input_stream.dart

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[coveralls]

coverage: 88.284% (-3.5%) from 91.739%
when pulling 42ca198 on objc_native
into b0e8676 on main.