Add patching script

[skip-ci]

.gitlab-ci/patch.sh

+#!/usr/bin/env bash
+
+set -e -o pipefail
+shopt -s nullglob
+
+unset REVERT
+
+err() {
+	( >&2 echo $@ )
+}
+
+usage() {
+	err "${0} [ -r] <patchdir> <target>"
+	exit 1
+}
+
+while getopts "r" opt; do
+	case $opt in
+		r) REVERT=1;;
+		*) usage;;
+	esac
+done
+
+shift $((OPTIND - 1))
+
+PATCHDIR="$1"
+TARGET="$2"
+
+[ -n "$PATCHDIR" ] && [ -d "$PATCHDIR" ] || {
+	err "Patchdir '${PATCHDIR}' is not a directory"
+	usage
+}
+
+[ -n "$TARGET" ] && [ -e "$TARGET" ] || {
+	err "Target '${TARGET}' does not exist"
+	usage
+}
+
+for file in "$PATCHDIR"/*.patch; do
+	if [ -z "$REVERT" ]; then
+		patch -d "$TARGET" -p1 < "$file"
+	else
+		patch -d "$TARGET" -p1 -R < "$file"
+	fi
+done