Coreutils with --enable-gcc-warnings does not build on Ubuntu 20.10
because matchpathcon is deprecated in favor of selabel_open etc.,
so this patch adds stubs for these functions.
* lib/se-label.c, lib/se-label.in.h, m4/selinux-label-h.m4: New files.
* lib/se-selinux.in.h (struct selinux_opt): Add incomplete decl,
as it is needed for selabel_open and selinux/selinux.h declares
this type here.
* modules/selinux-h (Files): Add the new files.
(configure.ac): Add gl_HEADERS_SELINUX_LABEL_H.
(lib_SOURCES): Add se-label.in.h, se-label.c.
(BUILT_SOURCES): Add $(SELINUX_LABEL_H).
(selinux/label.h): New rule, mimicking selinux/context.h.
(MOSTLYCLEANFILES): Add selinux/label.h, selinux/label.h-t.
(Include): Add selinux/label.h.