tree-wide: add SPDX headers and shebang

arch-chroot.in

@@ -1,4 +1,5 @@
 #!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-only
 
 shopt -s extglob
 

common

@@ -1,4 +1,7 @@
+#!/hint/bash
+# SPDX-License-Identifier: GPL-2.0-only
 # shellcheck disable=SC2059 # $1 and $2 can contain the printf modifiers
+
 out() { printf "$1 $2\n" "${@:3}"; }
 error() { out "==> ERROR:" "$@"; } >&2
 warning() { out "==> WARNING:" "$@"; } >&2

fstab-helpers

@@ -1,3 +1,6 @@
+#!/hint/bash
+# SPDX-License-Identifier: GPL-2.0-only
+
 # generated from util-linux source: libmount/src/utils.c
 declare -A pseudofs_types=([anon_inodefs]=1
                            [apparmorfs]=1

genfstab.in

@@ -1,4 +1,5 @@
 #!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-only
 
 shopt -s extglob
 

pacstrap.in

@@ -1,4 +1,5 @@
 #!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-only
 
 #
 # Assumptions: