hp malloc statistics: fix incorrect stats when configuring split buckets
(cherry picked from commit b68cfbab2716efe9bdcc3bfd1724b228ce84bda2)
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
(cherry picked from commit 42c3d383b1449af42a1ddfb91f4891f28fcbf50b)
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
	* also re-introduce fragment coalescing for pkg memory

(cherry-picked from commit 268955ba5af0306e849877aecc87967a0b6c7c3e)