* Make sure config.sub and config.guess are executable
This fixes Spack build on ppc64 and aarch64, see https://github.com/spack/spack/pull/21256
* Move config files after setting their mode
Co-authored-by: Frank Denis <124872+jedisct1@users.noreply.github.com>
The `which` command is not part of the posix standard and not available
in some environments. The `command` command is part of the posix
standard and well supported.
See https://unix.stackexchange.com/q/85249 for a discussion about the
use of `command` instead of `which`.
If a system had `libtool` but not `which`, the build process would issue
an erroneous error stating:
libtool is required, but wasn't found on this system
Switching to `command` corrects this problem.
