External API of gc::DHP class is changed: now only initial count
of hazard pointers can be specified in the constructor. Like new gc::HP,
the new gc::DHP supports an external allocator.
+ - Fixed a bug in BronsonAVLTreeMap::extract_min()/extract_max()/clear().
- Added more flat-combining queue tests, thanks to Marsel Galimullin.
- Changed cmake scripts to support MacOS and ARMv7/ARMv8 (64 bit),
thanks to Michail Komarov (https://github.com/Nemo1369)