Wrap linux specific syscalls 457 (listmount) and 458 (statmount)

Wrap linux specific syscalls 457 (listmount) and 458 (statmount)

The listmount syscall returns a list of mount IDs under the req.mnt_id.
This is meant to be used in conjunction with statmount(2) in order to
provide a way to iterate and discover mounted file systems.

The statmount syscall returns information about a mount, storing it in
the buffer pointed to by smbuf.  The returned buffer is a struct
statmount which is of size bufsize.

Declare a sys_{lis,sta}tmount wrapper in priv_syswrap-linux.h and hook it
for {amd64,arm,arm64,mips64,nanomips,ppc32,ppc64,riscv64,s390x,x86}-linux
using LINXY with PRE and POST handler in syswrap-linux.c

Both syscalls need CAP_SYS_ADMIN, to successfully test.

Resolves: https://bugs.kde.org/show_bug.cgi?id=502968