Mpersify parsers of readdir and getdents syscalls

Mpersify parsers of readdir and getdents syscalls

* defs.h (dirent_types): New xlat prototype.
* dirent.c: Stop including "xlat/direnttypes.h".
(kernel_dirent): New typedef.  Mpersify it.
(print_old_dirent): Use it instead of old_dirent_t.
(SYS_FUNC(getdents)): Use it instead of struct kernel_dirent.
Rename direnttypes to dirent_types.
(SYS_FUNC(getdents64)): Move ...
* dirent64.c: ... here.  Rename direnttypes to dirent_types.
Include "xlat/dirent_types.h".
* Makefile.am (strace_SOURCES): Add dirent64.c.
* xlat/direnttypes.in: Rename to xlat/dirent_types.in.