hp malloc statistics: fix incorrect stats when configuring split buckets
core statistics: export a initialization checking function

	* this allows statistics-dependent code to test initialization
	* change all "shm_malloc" calls to "shm_malloc_unsafe"

	* ultimately, memory allocators are now able to make use of core stats
hp malloc: differentiate the pkg and shm statistics code

When HP_MALLOC is defined:
	* shm statistics are based on 32/64-bit atomic counters
			- the former logic is still available with HP_MALLOC_FAST_STATS
			- however, stat aggregation and the shm threshold checks should be done by a single process
	* pkg statistics are implemented similarly to the other allocators