Add portable function name helper

[aobolensk]

• Add PPC_FUNC_NAME macro providing compiler agnostic pure function name
• Replace __builtin_FUNCTION() with PPC_FUNC_NAME macro in task.hpp

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.17%. Comparing base (81c3284) to head (1fb91c1).
Report is 11 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #446      +/-   ##
==========================================
- Coverage   92.37%   92.17%   -0.21%     
==========================================
  Files          11       11              
  Lines         354      396      +42     
  Branches      124      150      +26     
==========================================
+ Hits          327      365      +38     
  Misses         10       10              
- Partials       17       21       +4     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.