Name native threads before start (macOS/Native AOT)

[eduardo-vp]

Fixes #106464.

[Copilot]

Copilot reviewed 1 out of 1 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

src/libraries/System.Private.CoreLib/src/System/Threading/Thread.cs:140

• The assignment to _startHelper._thread = this is repeated in several constructors wrapped in #if TARGET_OSX. Consider refactoring this repeated pattern into a helper method to reduce duplication and simplify maintenance.

_startHelper = new StartHelper(start);

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[jkotas]

ThreadNameChanged sets the OS thread name, and also notifies profiler and debugger on CoreCLR about the thread name change. These notifications are superfluous here. I am not sure whether it matters.

[jkotas]

Do we need a test (https://github.com/dotnet/runtime/blob/main/src/libraries/System.Threading.Thread/tests/ThreadTests.cs)?

[eduardo-vp]

Since checking the native thread name is platform specific rather than cross-platform and also there were errors in some Windows legs about not finding the native methods in kernel32.dll, I think we could merge this change without adding a test. It was manually validated for OSX/Native AOT.

[jkotas]

Thanks!