In order to make it easier to support CloudABI on ARM64, move out all of
the bits from the AMD64 cloudabi_sysvec.c into a new file
cloudabi_module.c that would otherwise remain identical. This reduces
the AMD64 specific code to just ~160 lines.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D3974
MACHINE_CPUARCH expands to aarch64 for arm64, whereas MACHINE always
corresponds to the directory name under sys/ that contains the sources
for that architecture.
Place all of the machine/pointer size independent code in a kernel
module called 'cloudabi'. All of the 64-bit specific code goes in a
separate module called 'cloudabi64'. The latter is only enabled on
amd64, as it is the only architecture supported.
