Improve performance on Apple M1 Vortex

Big Endian Changes for Power10 kernels

Fix minor typo in Makefile.system

Fix detection of Apple M1 "Vortex"

Merge 0.3.18 back into develop to copy tag

Merge from develop for 0.3.18

* Update Changelog for 0.3.18

Update Alpine version used in Azure CI

Fix out of bounds read in ?llarv (Reference-LAPACK PR 625)

Make sure that Netlib LAPACK respects FFLAGS

OpenBLAS allows users to specify `FFLAGS` and then uses `override` to append additional
options. However, without such an override in lapack's make.inc, lapack would use the external
FFLAGS, rather than the ones being computed by OpenBLAS. For example the `DEBUG=1` flag
would not apply to LAPACK code. This is all a bit messy but forced by the integration with netlib
lapack. Note that `CFLAGS` already has this override for the same reason. It is possible that
other variables here should have a similar override, but I think for most of the other ones, OpenBLAS's
build system does not append to the flags passed in by the user.

x86_64: BFLOAT16: fix build warning

Makefile.system: adjust mipsel/mips64el ARCH variables