It would be nice if there was a way to tell compilers not to drop the lock stack and thus issue warnings when accessing a symbol that needs a lock inside `Assume`/`Assert`.

Hit by (at least): @ajtowns , @jnewbery , me.
BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int32_t>("+-1"), 0);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int32_t>("-+1"), 0);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int32_t>("++1"), 0);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int32_t>("--1"), 0);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int32_t>(""), 0);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int32_t>("aap"), 0);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int32_t>("0x1"), 0);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int32_t>("-32482348723847471234"), -2'147'483'647 - 1);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int32_t>("32482348723847471234"), 2'147'483'647);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int64_t>("-9223372036854775809"), -9'223'372'036'854'775'807LL - 1LL);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int64_t>("-9223372036854775808"), -9'223'372'036'854'775'807LL - 1LL);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int64_t>("9223372036854775807"), 9'223'372'036'854'775'807);
    BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int64_t>("9223372036854775808"), 9'223'372'036'854'775'807);
    std::map<std::string, int64_t> atoi64_test_pairs = {
        {"-9223372036854775809", std::numeric_limits<int64_t>::min()},
        {"-9223372036854775808", -9'223'372'036'854'775'807LL - 1LL},
        {"9223372036854775807", 9'223'372'036'854'775'807},
        {"9223372036854775808", std::numeric_limits<int64_t>::max()},
        {"+-", 0},
        {"0x1", 0},
        {"ox1", 0},
        {"", 0},
    };
    for (const auto& pair : atoi64_test_pairs) {
        BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int64_t>(pair.first), pair.second);
    }
    
    for (const auto& pair : atoi64_test_pairs) {
        BOOST_CHECK_EQUAL(LocaleIndependentAtoi<int64_t>(pair.first), atoi64_legacy(pair.first));
    }