add selftest for statmount/listmount

Initial selftest for the new statmount() and listmount() syscalls.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Link: https://lore.kernel.org/r/20231213161104.403171-1-mszeredi@redhat.comSigned-off-by: Christian Brauner <brauner@kernel.org>

tools/testing/selftests/Makefile

@@ -26,6 +26,7 @@ TARGETS += filesystems
 TARGETS += filesystems/binderfs
 TARGETS += filesystems/epoll
 TARGETS += filesystems/fat
+TARGETS += filesystems/statmount
 TARGETS += firmware
 TARGETS += fpu
 TARGETS += ftrace

tools/testing/selftests/filesystems/statmount/.gitignore

+# SPDX-License-Identifier: GPL-2.0-only
+/*_test

tools/testing/selftests/filesystems/statmount/Makefile

+# SPDX-License-Identifier: GPL-2.0-or-later
+
+CFLAGS += -Wall -O2 -g $(KHDR_INCLUDES)
+TEST_GEN_PROGS := statmount_test
+
+include ../../lib.mk