[native_toolchain_c] Include missing errors output using Level.INFO when running CL

[poirierlouis]

CL outputs error-related messages to the standard output. This patch allows outputting these errors to the user while preserving the current level of logging for other toolchains.

Closes #2809

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[dcharkes]

Could you add a test or change an existing test to see that your change has the desired effect?

[github-actions]

PR Health

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.

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pkgs/objective_c/example/command_line/lib/main.dart
pkgs/objective_c/lib/src/ns_input_stream.dart

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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 symbol	Leaking sources

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Breaking changes ✔️

Package	Change	Current Version	New Version	Needed Version	Looking good?
native_toolchain_c	None	0.17.3	0.17.4	0.17.3	✔️

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[coveralls]

coverage: 81.832% (-5.1%) from 86.974%
when pulling 132221d on poirierlouis:fix/missing-logs
into 224d93e on dart-lang:main.

[poirierlouis]

Could you add a test or change an existing test to see that your change has the desired effect?

I added a test + changelog + pubspec, it should be all good now.

[github-actions]

Package publishing

Package	Version	Status	Publish tag (post-merge)
package:code_assets	1.0.0	already published at pub.dev
package:data_assets	0.19.6	already published at pub.dev
package:ffi	2.1.5-wip	WIP (no publish necessary)
package:hooks	1.0.0	already published at pub.dev
package:hooks_runner	1.0.0	already published at pub.dev
package:native_toolchain_c	0.17.4	ready to publish	native_toolchain_c-v0.17.4
package:swift2objc	0.1.0	already published at pub.dev
package:swiftgen	0.1.1	already published at pub.dev

Documentation at https://github.com/dart-lang/ecosystem/wiki/Publishing-automation.

[dcharkes]

Thanks @poirierlouis ! 🙏