configure script can't auto-detect aarch64

[MrHighVoltage]

Same issue as I raised for cbc, the config.sub and config.guess files have been regularly updated in this repo, but not in the releases. This requires to manually set the build target when calling the configure script when building for architectures, that have not existed back in 2007 (when the named files have last been updated).

Is it possible to update those files and re-release the current version of Symphony?

Thank you!

[tkralphs]

See coin-or/Cbc#587.

[tkralphs]

Apparently, it works to do this.