Move sysent shorthand notations to separate files

Move sysent shorthand notations to separate files

Avoid proliferation of exactly the same definitions of shorthand
notations for macros defined in sysent.h by moving definitions
and undefs of these shorthand notations to separate files.

* sysent_shorthand_defs.h: New file.
* sysent_shorthand_undefs.h: Likewise.
* Makefile.am (strace_SOURCES): Add them.
* syscall.c: Use them.

Signed-off-by: Edgar Kaziakhmedov <edgar.kaziakhmedov@virtuozzo.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>