Enable a default native ARCH

uses a posix compatible script to find the native arch.
(based on ppigazzini's https://github.com/ppigazzini/stockfish-downloader )
use that native arch by default, no changes if ARCH is specified explicitly.

SF can now be compiled in an optimal way simply using

make -j profile-build

closes https://github.com/official-stockfish/Stockfish/pull/4777

No functional change

scripts/get_native_properties.sh

@@ -0,0 +1,121 @@
+#!/bin/sh
+
+#
+# Returns properties of the native system.
+# best architecture as supported by the CPU
+# filename of the best binary uploaded as an artifact during CI
+#
+
+# Check if all the given flags are present in the CPU flags list
+check_flags() {
+  for flag; do
+    printf '%s\n' "$flags" | grep -q -w "$flag" || return 1
+  done
+}
+
+# Set the CPU flags list
+get_flags() {
+  flags="$(awk '/^flags[ \t]*:/{gsub(/^flags[ \t]*:[ \t]*/, ""); line=$0} END{print line}' /proc/cpuinfo) $(awk '/^Features[ \t]*:/{gsub(/^Features[ \t]*:[ \t]*/, ""); line=$0} END{print line}' /proc/cpuinfo)"
+  # remove underscores and points from flags, e.g. gcc uses avx512vnni, while some cpuinfo can have avx512_vnni, some systems use sse4_1 others sse4.1
+  flags=$(printf '%s' "$flags" | sed "s/[_.]//g")
+}
+
+# Check for gcc march "znver1" or "znver2" https://en.wikichip.org/wiki/amd/cpuid
+check_znver_1_2() {
+  vendor_id=$(awk '/^vendor_id/{print $3; exit}' /proc/cpuinfo)
+  cpu_family=$(awk '/^cpu family/{print $4; exit}' /proc/cpuinfo)
+  [ "$vendor_id" = "AuthenticAMD" ] && [ "$cpu_family" = "23" ] && znver_1_2=true
+}
+
+# Set the file CPU x86_64 architecture
+set_arch_x86_64() {
+  if check_flags 'avx512vnni' 'avx512dq' 'avx512f' 'avx512bw' 'avx512vl'; then
+    true_arch='x86-64-vnni256'
+  elif check_flags 'avx512f' 'avx512bw'; then
+    true_arch='x86-64-avx512'
+  elif [ -z "${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
+}
+
+# Check the system type
+uname_s=$(uname -s)
+uname_m=$(uname -m)
+case $uname_s in
+  'Darwin') # Mac OSX system
+    case $uname_m in
+      'arm64')
+        true_arch='apple-silicon'
+        file_arch='x86-64-sse41-popcnt' # Supported by Rosetta 2
+        ;;
+      'x86_64')
+        flags=$(sysctl -n machdep.cpu.features machdep.cpu.leaf7_features | tr '\n' ' ' | tr '[:upper:]' '[:lower:]' | sed "s/[_.]//g")
+        set_arch_x86_64
+        if [ "$true_arch" = 'x86-64-vnni256' ] || [ "$true_arch" = 'x86-64-avx512' ]; then
+           file_arch='x86-64-bmi2'
+        fi
+        ;;
+    esac
+    file_os='macos'
+    file_ext='tar'
+    ;;
+  'Linux') # Linux system
+    get_flags
+    case $uname_m in
+      'x86_64')
+        file_os='ubuntu'
+        check_znver_1_2
+        set_arch_x86_64
+        ;;
+      'i686')
+        file_os='ubuntu'
+        true_arch='x86-32'
+        ;;
+      'aarch64')
+        file_os='android'
+        true_arch='armv8'
+        if check_flags 'dotprod'; then
+          true_arch="$true_arch-dotprod"
+        fi
+        ;;
+      'armv7'*)
+        file_os='android'
+        true_arch='armv7'
+        if check_flags 'neon'; then
+          true_arch="$true_arch-neon"
+        fi
+        ;;
+      *) # Unsupported machine type, exit with error
+        printf 'Unsupported machine type: %s\n' "$uname_m"
+        exit 1
+        ;;
+    esac
+    file_ext='tar'
+    ;;
+  'CYGWIN'*|'MINGW'*|'MSYS'*) # Windows system with POSIX compatibility layer
+    get_flags
+    check_znver_1_2
+    set_arch_x86_64
+    file_os='windows'
+    file_ext='zip'
+    ;;
+  *)
+    # Unknown system type, exit with error
+    printf 'Unsupported system type: %s\n' "$uname_s"
+    exit 1
+    ;;
+esac
+
+if [ -z "$file_arch" ]; then
+  file_arch=$true_arch
+fi
+
+file_name="stockfish-$file_os-$file_arch.$file_ext"
+
+printf '%s %s\n' "$true_arch" "$file_name"