* std::pair<> does not guarantee stable layout
* we need to have constructor which takes only one value and
  default intializes the second value in pair (it's needed for
  insert which only takes key)

It is more obvious that on_init_size is always consistent this way.

to runtime_initialize()

So that the initialization is only in one place.

in runtime_initialize

It will protect user in case of accidentaly changing size of key
or value.

tests: fix transaction test

We did not set counter to a proper value which caused failure on
older std libs (for example in rhel-7.7)

Add simple hash_map benchmark for opening time

concurrent_hash_map: change implementation of runtime_initialize(bool)

This patch changes implementation to be the same as before
708bd019 (implementation of
runtime_initialize(void) is left unchanged).

The change is needed for backward compatibility with pmemkv-1.0. There, we
called runtime_initialize(true) in a transaction after tx commit (we assumed
there is nothing transactional in runtime_initialize). Introducing a tx
inside new runtime_initialize() results in crash on 1.0

Update PMDK to newest devel-1.8

tests: increase poolsize for enumerable_thread_specific access test

in some runs (depending on thread scheduling) test ended with out-of-memory
error.

It measures mainly runtime_initialize() time.

Fix delete_persistent to be called properly, on object, in ptr test

Add defragmentation feature

Can be used to iterate over all internal vector's pointers.
It's used i.a. in defrag class for storing all ptrs
in internal list for defragmentation process.

Add a defrag class, which holds pointers which will be a subject
of a defragmentation process, using libpmemobj's pmemobj_defrag()

ref. pmem/pmdk#4066

Hash map consistent size feature

The bool parameter is not needed anymore, size is always restored from
'consistent_size'.

using enumerable_thread_local.

they will be set inside tx so we need p<>.

Implementation of insert_or_assign in concurrent_hash_map

Fix regression in add_test_generic()

Remove duplicated cmake scripts

Add compatibility tests (with different libpmemobj-cpp versions)

Fix tests_clang_release_cpp11_no_valgrind in run-build.sh

Fix types in enumerable_thread_specific_access test

On travis, without this flag rm asks for input if it should
"remove write-protected regular file".

Set CMAKE_BUILD_TYPE to Release instead of Debug.

typo fixes

It fixes the following compilation error on openSUSE Leap:
In file included from /libpmemobj-cpp/tests/enumerable_thread_specific_access/enumerable_thread_specific_access.cpp:33:0:
/libpmemobj-cpp/tests/enumerable_thread_specific_access/enumerable_thread_specific_access.cpp: In function 'void test(pmem::obj::pool<root>&)':
/libpmemobj-cpp/tests/enumerable_thread_specific_access/enumerable_thread_specific_access.cpp:100:19: error: conversion to 'size_t {aka long unsigned int}' from 'int' may change the sign of the result [-Werror=sign-conversion]
   UT_ASSERT(n_100 + n_zeros == concurrency);
             ~~~~~~^~~
/libpmemobj-cpp/tests/common/unittest.hpp:130:11: note: in definition of macro 'UT_ASSERT'
  ((void)((cnd) ||                                                       \
           ^~~

The add_test_common() function requires the TEST_CASE variable
to be defined.
It fixes regression introduced by b969cb5f.

Insert_or_assign from std::unordered_map (since C++17) without hints, additional method with heterogeneous key-type and tests