It's possible to detect the architecture from the target triple, but
there are a number of exceptions that make it unpleasant to use for this
purpose. There are just too many weird exceptions (like mips vs mipsel,
and armv6m vs thumv6m vs arm64 vs aarch64) so it's better to centralize
these to canonical architecture names.
I picked the architecture names that happen to match the musl
architecture names, because those seem the most natural to me.
Ayke van Laethem
fb3d98ce6e