These ones are irrelevant to the config but rather to the platform, and
as such are better placed in compiler.h.
Here we take the opportunity for declaring a few extra capabilities:
- HA_UNALIGNED : CPU supports unaligned accesses
- HA_UNALIGNED_LE : CPU supports unaligned accesses in little endian
- HA_UNALIGNED_FAST : CPU supports fast unaligned accesses
- HA_UNALIGNED_ATOMIC : CPU supports unaligned accesses in atomics
This will help remove a number of #ifdefs with arch-specific statements.