xxhash: Add SOVERSION guard

%ci:no-build

packages/xxhash/build.sh

@@ -7,3 +7,15 @@ TERMUX_PKG_SRCURL=https://github.com/Cyan4973/xxHash/archive/v${TERMUX_PKG_VERSI
 TERMUX_PKG_SHA256=3bb6b7d6f30c591dd65aaaff1c8b7a5b94d81687998ca9400082c739a690436c
 TERMUX_PKG_AUTO_UPDATE=true
 TERMUX_PKG_BUILD_IN_SRC=true
+
+termux_step_post_massage() {
+	# Do not forget to bump revision of reverse dependencies and rebuild them
+	# after SOVERSION is changed.
+	local _SOVERSION_GUARD_FILES="lib/libxxhash.so.0"
+	local f
+	for f in ${_SOVERSION_GUARD_FILES}; do
+		if [ ! -e "${f}" ]; then
+			termux_error_exit "SOVERSION guard check failed."
+		fi
+	done
+}