Added script to cherry-pick a commit to multiple tags

tools/cherry_pick_to_tags.sh

@@ -0,0 +1,55 @@
+#!/bin/sh
+# Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+# file at the top-level directory of this distribution and at
+# http://rust-lang.org/COPYRIGHT.
+#
+# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+# option. This file may not be copied, modified, or distributed
+# except according to those terms.
+
+# Exit if anything fails
+set -e
+
+if [ "$#" -lt 2 ]; then
+    echo "Usage: $0 COMMIT_HASH TAGS" >&2
+    exit 1
+fi
+
+branch_name=$(git symbolic-ref -q HEAD)
+branch_name=${branch_name##refs/heads/}
+branch_name=${branch_name:-HEAD}
+
+commit="$1"
+
+echo "current branch $branch_name"
+echo "commit hash $commit"
+
+shift
+
+for tag in "$@"; do
+    echo "UPDATING TAG $tag"
+    {
+        # backup the tag in case it doesn't exist in origin
+        git tag backup_"$tag" "$tag"
+        # delete it to get the most recent version from origin
+        git tag -d "$tag"
+        git fetch --tags
+        git branch tmp_update_tag_"$tag" "$tag"
+        # the tag seems exists in origin, delete the backup
+        git tag -d backup_"$tag"
+
+        # cherry pick commit and update tag
+	git checkout tmp_update_tag_"$tag"
+        git cherry-pick -x "$commit"
+        git tag -f "$tag" HEAD
+
+        # switch back to previous branch
+        git checkout "$branch_name"
+        git branch -D tmp_update_tag_"$tag"
+
+        # push the updated tag
+        git push origin "$tag" --force
+    } >/dev/null
+done