Add rust-bindgen's friends.sh to scripts/

I run something similar to get each releases' contributor names, and
rust-bindgen happens to have this in a script, so let's import it.

Signed-off-by: Manos Pitsidianakis <manos@pitsidianak.is>

scripts/friends.sh

@@ -0,0 +1,55 @@
+#!/usr/bin/env bash
+
+# BSD 3-Clause License
+#
+# Copyright (c) 2013, Jyun-Yan You
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# * Redistributions of source code must retain the above copyright notice, this
+#   list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright notice,
+#   this list of conditions and the following disclaimer in the documentation
+#   and/or other materials provided with the distribution.
+#
+# * Neither the name of the copyright holder nor the names of its
+#   contributors may be used to endorse or promote products derived from
+#   this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# Original from rust-bindgen repository, commit SHA c8e237f54370bdc1777df2c5d08eccf7ec5c33fc
+
+set -eu
+set -o pipefail
+
+cd "$(dirname "${0}")"
+
+if [[ -z "${1+x}" ]]; then
+    read -r -p "List friends since which commit/tag? " since
+    echo
+else
+    since=$1
+fi
+
+git shortlog -s -n "${since}.." \
+    | cut -f 2- \
+    | sort \
+        --ignore-case \
+        --dictionary-order \
+        --stable \
+        --ignore-leading-blanks \
+        --unique \
+    | xargs -I{} echo "- {}"