Small improvement to Linux build script.

etc/utils/build-linux.sh

@@ -2,12 +2,20 @@
 set -e
 cd -- "$(dirname -- "${BASH_SOURCE[0]}")/../.."
 
+readonly mode="${1,,}"
+if [[ "${mode}" != "gnu" && "${mode}" != "musl" ]]; then
+	echo "Error: Parameter must be either \"gnu\" or \"musl\" !!!"
+	exit 1
+fi
+
 rm -rf "out"
 mkdir -pv "out/include"
 cp -rfv "libhashset/include/"*.h "out/include"
 
-for target in i686 x86_64 arm64; do
+case "${mode}" in
-	compiler="/usr/local/musl/${target}/bin/musl-gcc"
+	gnu)
+		for target in i686 x86_64 aarch64; do
+			compiler="${target}-linux-gnu-gcc"
 			target="$("${compiler}" -dumpmachine)"
 			echo -e "--------------------------------\n${target}\n--------------------------------"
 			make CC="${compiler}" clean
@@ -19,4 +27,22 @@ for target in i686 x86_64 arm64; do
 					cp -fv "${i}/${j}/bin/${i}-${j}" "out/bin/${target}"
 				done
 			done
-done
+		done
+		;;
+	musl)
+		for target in i686 x86_64 arm64; do
+			compiler="/usr/local/musl/${target}/bin/musl-gcc"
+			target="$("${compiler}" -dumpmachine | sed 's/-gnu/-musl/i')"
+			echo -e "--------------------------------\n${target}\n--------------------------------"
+			make CC="${compiler}" clean
+			make CC="${compiler}"
+			mkdir -pv "out/lib/${target}" "out/bin/${target}"
+			cp -rv "libhashset/lib/"* "out/lib/${target}"
+			for i in example test; do
+				for j in hash-set hash-map; do
+					cp -fv "${i}/${j}/bin/${i}-${j}" "out/bin/${target}"
+				done
+			done
+		done
+		;;
+esac