test_mutex (Transaction test, Speculative Spin Mutex) fails under gcc 11

[anton-potapov]

compiled with gcc 11 ( make ~/git/onetbb/ -G Ninja -DCMAKE_CXX_COMPILER=g++-11 -DCMAKE_C_COMPILER=gcc-11 ), test gives this:

[doctest] doctest version is "2.4.7"
[doctest] run with "--help" for options
===============================================================================
/home/anton/git/onetbb/test/tbb/test_mutex.cpp:114:
TEST CASE:  Transaction test

/home/anton/git/onetbb/test/tbb/test_mutex.cpp:109: FATAL ERROR: REQUIRE( n_transactions_attempted.load(std::memory_order_relaxed) ) is NOT correct!
  values: REQUIRE( 0 )
  logged: ERROR for Speculative Spin Mutex: transactions were never attempted

===============================================================================
[doctest] test cases:      12 |      11 passed | 1 failed | 0 skipped
[doctest] assertions: 1215017 | 1215016 passed | 1 failed |
[doctest] Status: FAILURE!