NetBSD/aarch64 version (which we maintain locally) is kept back at
1.17.8nb1 since it works OK for bootstrap and I don't feel like regen'ing
the binaries unless there is some bug that warrants it.
Unfortunately stripping the signatures breaks running the binaries outside a
chroot according to schmonz, so we're left with no choice but to make this
user-configurable. It took a lot of effort for me not to name this variable
something far ruder.
This will still mean the go-bin package is ultimately useless when shipped as
part of a package set, but really we only need it for bootstrapping a real
version which should work fine.
This uses go-1.16.beta1, which is the first (beta) release to natively
support Apple Silicon on macOS.
Discussed and tested on tech-pkg@.
Note that more is missing to be able to use Go 1.16 to build packages on
Darwin/aarch64 (or arm64).
