proc/threads: let _proc_lockTry relock a recursive mutex

[julianuziemblo]

YT: RTOS-1334

Description

related: phoenix-rtos/libphoenix#477

Tests:
Depends-On: phoenix-rtos-tests:julianuziemblo/CI-676

Motivation and Context

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Chore (refactoring, style fixes, git/CI config, submodule management, no code logic changes)

How Has This Been Tested?

• Already covered by automatic testing.
• New test added: sys/mutex: add tests for mutexTry on recursive lock phoenix-rtos-tests#489
• Tested by hand on: ia32-generic-qemu

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing linter checks and tests passed.
• My changes generate no new compilation warnings for any of the targets.

Special treatment

• This PR needs additional PRs to work (list the PRs, preferably in merge-order).
• I will merge this PR by myself when appropriate.

[gemini-code-assist]

Code Review

This pull request introduces recursive locking support in the _proc_lockTry function within proc/threads.c. It adds logic to increment a lock's depth if the current thread already owns a recursive lock. The review feedback identifies a missing overflow check for the lock depth, suggesting an assertion, and recommends using the equality operator for type checks to ensure consistency with the repository's style.

[github-actions]

Unit Test Results

10 585 tests  +42   9 915 ✅ +34   52m 48s ⏱️ + 1m 35s
   649 suites ± 0     670 💤 + 8 
     1 files   ± 0       0 ❌ ± 0 

Results for commit cdf9af4. ± Comparison against base commit 32d04db.

♻️ This comment has been updated with latest results.

[etiaro]

You could try to share some of this code with _proc_lockSet, to reduce chance of such oversights in the future.