Use ARM_UNIFIED_THREAD_STATE in the call to thread_get_state() on iOS7 64-bit
and up and iOS8 32-bit and up.
Merge remote-tracking branch 'robovm/thread_get_state_stack_corruption_on_ios7_64bit_and_ios8'

Conflicts:
	darwin_stop_world.c
Fix mistyped ARM_THREAD_STATE macro (Darwin/arm)

* include/private/gc_priv.h (GC_MACH_THREAD_STATE,
GC_MACH_THREAD_STATE_COUNT): Define to ARM_THREAD_STATE[_COUNT],
respectively, instead of mistyped ARM_MACHINE_THREAD_STATE[_COUNT]
(if DARWIN and ARM32).