limit arm8.5 on musllinux

Author: mattip

tools/build_steps.sh

@@ -139,7 +139,11 @@ function do_build_lib {
         Linux-aarch64)
             local bitness=64
             local target_flags="TARGET=ARMV8"
-            export CFLAGS="$CFLAGS -march=armv8.6-a+sve"
+            if [ "$MB_ML_LIBC" == "musllinux" ]; then
+                export CFLAGS="$CFLAGS -march=armv8.5-a+sve"
+            else
+                export CFLAGS="$CFLAGS -march=armv8.6-a+sve"
+            fi
             ;;
         Darwin-arm64)
             local bitness=64