tests: skip tests because DevDAX is too big & similar cases

[osalyk]

ISSUE: pmempool tests are skipped because DevDAX is too big

Actual behavior:

[janekmi]

A similar case is with pmempool_check/TEST20-23 which requires simply:

require_dax_devices 1
configure_valgrind memcheck force-enable $PMEMPOOL$EXESUFFIX

But since the provided device DAX is going to be mmap'ed into an anonymous mapping in its entirety. It is required to run the test to be able to create an anonymous mapping of specific size under Valgrind. Which is possible or impossible depending on the order of the device DAX'es provided in testoconfig.sh and their sizes.

This condition is checked currently by the setup function by calling require_mmap_under_valgrind which compares the number of the required device DAX'es against the number of device DAX'es that were possible to fit into a single anonymous allocation. Please see here and here. Note: the device DAX'es are not mmap'ed, just the big enough anonymous mapping is created under Valgrind.

The key thing is: that the order of device DAXes in the config determines the number of device DAXes that are available to use under Valgrind.

Preview

https://github.com/pmem/pmdk/actions/runs/5707910977/job/15465055888#step:3:12807

pmempool_check/TEST20: SKIP: anonymous mmap under Valgrind not possible for 1 DAX device(s).

[janekmi]

Next steps: List all tests which are affected by this issue.