tests: Add SPDX license headers automatically

Add SPDX license (but not copyright) headers to all files which follow a
certain pattern in their existing non-machine-readable header comment.

This commit was entirely generated using the command:
```
git ls-files gobject/tests/*.[ch] | xargs perl -0777 -pi -e 's/\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/\n \*\n \* SPDX-License-Identifier: LGPL-2.1-or-later\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/igs'
```

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

Helps: #1415

gobject/tests/accumulator.c

@@ -1,6 +1,8 @@
 /* GObject - GLib Type, Object, Parameter and Signal Library
  * Copyright (C) 2001, 2003 Red Hat, Inc.
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/basic-signals.c

@@ -2,6 +2,8 @@
  * Copyright (C) 2013 Red Hat, Inc.
  * Copy and pasted from accumulator.c and modified.
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/bindinggroup.c

@@ -3,6 +3,8 @@
  * Copyright (C) 2015-2022 Christian Hergert <christian@hergert.me>
  * Copyright (C) 2015 Garrett Regier <garrettregier@gmail.com>
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/defaultiface.c

@@ -1,6 +1,8 @@
 /* GObject - GLib Type, Object, Parameter and Signal Library
  * Copyright (C) 2001, 2003 Red Hat, Inc.
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/deftype.c

@@ -1,6 +1,8 @@
 /* deftype.c
  * Copyright (C) 2006 Behdad Esfahbod
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/dynamictype.c

@@ -1,6 +1,8 @@
 /* GObject - GLib Type, Object, Parameter and Signal Library
  * Copyright (C) 2001, 2003 Red Hat, Inc.
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/flags.c

@@ -1,6 +1,8 @@
 /* flags.c
  * Copyright (C) 2018 Arthur Demchenkov
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/ifaceproperties.c

@@ -1,6 +1,8 @@
 /* GObject - GLib Type, Object, Parameter and Signal Library
  * Copyright (C) 2001, 2003 Red Hat, Inc.
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/override.c

@@ -3,6 +3,8 @@
  * Copyright (C) 2001, James Henstridge
  * Copyright (C) 2003, Red Hat, Inc.
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/param.c

@@ -1,6 +1,8 @@
 /* GLIB - Library of useful routines for C programming
  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/references.c

@@ -1,6 +1,8 @@
 /* GObject - GLib Type, Object, Parameter and Signal Library
  * Copyright (C) 2005 Red Hat, Inc.
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/signalgroup.c

@@ -3,6 +3,8 @@
  * Copyright (C) 2015-2022 Christian Hergert <christian@hergert.me>
  * Copyright (C) 2015 Garrett Regier <garrettregier@gmail.com>
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/singleton.c

@@ -1,6 +1,8 @@
 /* GObject - GLib Type, Object, Parameter and Signal Library
  * Copyright (C) 2006 Imendio AB
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/testcommon.h

@@ -1,6 +1,8 @@
 /* GObject - GLib Type, Object, Parameter and Signal Library
  * Copyright (C) 2003 Red Hat, Inc.
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/testing.c

@@ -2,6 +2,8 @@
  *
  * Copyright © 2019 Endless Mobile, Inc.
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/testmodule.c

@@ -2,6 +2,8 @@
  * testmodule.c: Dummy dynamic type module
  * Copyright (C) 2003 Red Hat, Inc.
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/testmodule.h

@@ -2,6 +2,8 @@
  * testmodule.h: Dummy dynamic type module
  * Copyright (C) 2003 Red Hat, Inc.
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

gobject/tests/value.c

@@ -1,6 +1,8 @@
 /* GLIB - Library of useful routines for C programming
  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
  *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either