Outdated config.sub breaks compilation on macOS aarch64

[Jarred Sumner]

To reproduce, run this on an M1:

git clone https://github.com/ianlancetaylor/libbacktrace
cd libbacktrace
./configure

The error it reports is:

checking build system type... Invalid configuration `arm64-apple-darwin21.2.0': machine `arm64-apple' not recognized
configure: error: /bin/sh ./config.sub arm64-apple-darwin21.2.0 failed

If you copy paste the latest config.sub from gcc, then ./configure and make run successfully.

For reference, the config.sub I used was from here

[Ian Lance Taylor]

Thanks. I updated the configury files.