As observed using GCC 10 using -march=native -ftree-vectorize
on Knights Landing, it is now smart enough to find clobbers inside
non-inlined static functions.

In particular, sgemv counted on a kernel to preserve the whole
%ymm2 register (since it was not in the clobber list), but the top
part was destroyed by vzeroupper. This caused many tests to fail.

This patch makes sure all xmm (and ymm/zmm by extension) registers
are listed as clobbered to avoid this happening, as most kernels
already did correctly in fact.

Put back all symbols accidentally dropped in the reorganization of gensymbol

Clean up duplicate definitions in POWER8 kernels and fix power10 option passing

rebase

Fix exporting some lapack and cblas symbols

sgemm_direct_skylakex: fix 75eeb26 regression.

Support cross-compiling for Apple Vortex

The
`#if defined(SKYLAKEX) || defined (COOPERLAKE)`
from that commit was before #include "common.h" so caused the
compiled function to be empty, returning garbage results for
qualifying sgemm's on those architectures.

Closes #2914

Need a space when redirecting to file

rebase

Following two commands have two completely different meanings
perl ./gensymbol objcopy x86_64 _ 0 0  0 0 0 0 "" "64_" 1 0 1 1 1 1 > objcopy.def
perl ./gensymbol objcopy x86_64 _ 0 0  0 0 0 0 "" "64_" 1 0 1 1 1 1> objcopy.def

Synchronyse tag with release 0.3.11

Update from develop for 0.3.11

Update Changelog.txt with the 0.3.11 changes

Add -mavx for clang & aocc

rebase

Add compiler options for SSE to the cmake support files

More pre-release fixes

rebase

Add compiler flag for SSE4 where available

Add double precision universal intrinsics for X86/ARM