[Enhancement] Allow bounded queue size to exceed 65,535 for 64bit systems

[yuvalif]

in https://github.com/boostorg/lockfree/blob/develop/include/boost/lockfree/detail/freelist.hpp lines 335 and 369, replace the numeric const with compile time const derived from 32bit vs. 64bit compilation (e.g. #if __x86_64__ || __ppc64__ )