Remove duplicate flags in Makefile

[mstembera]

No functional change
bench: 2746404

[vondele]

The original idea was that the -mfoo flags correspond to

Stockfish/scripts/get_native_properties.sh

Lines 40 to 57 in ee243f0

	# Set the file CPU x86_64 architecture
	set_arch_x86_64() {
	if check_flags 'avx512f' 'avx512cd' 'avx512vl' 'avx512dq' 'avx512bw' 'avx512ifma' 'avx512vbmi' 'avx512vbmi2' 'avx512vpopcntdq' 'avx512bitalg' 'avx512vnni' 'vpclmulqdq' 'gfni' 'vaes'; then
	true_arch='x86-64-avx512icl'
	elif check_flags 'avx512vnni' 'avx512dq' 'avx512f' 'avx512bw' 'avx512vl'; then
	true_arch='x86-64-vnni512'
	elif check_flags 'avx512f' 'avx512bw'; then
	true_arch='x86-64-avx512'
	elif [ -z "${znver_1_2+1}" ] && check_flags 'bmi2'; then
	true_arch='x86-64-bmi2'
	elif check_flags 'avx2'; then
	true_arch='x86-64-avx2'
	elif check_flags 'sse41' && check_flags 'popcnt'; then
	true_arch='x86-64-sse41-popcnt'
	else
	true_arch='x86-64'
	fi
	}

so that we have a 1-to-1 matching of these two and we are explicit. We might have moved away from that, but I think that is not a bad practice. What do you think?

[mstembera]

Hmm I know almost nothing about the scripts and where the flags that are fed to them aggregate come from so I can't make any good suggestions there. I can only speak to the consistency of the Makefile which seems inconsistent for VNNI512 and AVX512ICL compared to the other archs. The normal Makefile set up seems to be that each successively more modern arch only adds new flags on top of the older archs without redefining the older flags again. For example AVX2 assumes the SSE41 flags are already defined, SSE41 assumes the SSSE3 flags are already defined, and so on. VNNI512 and AVX512ICL seem to break this principle by redefining what was already defined. If this is somehow necessary because of how the scripts work I can close this PR or make any changes you suggest.