* sysdeps/unix/sysv/linux/siglist.c: Moved to ...
* sysdeps/gnu/siglist.c: ... here.
Use <siglist.h> instead of "siglist.h", to ensure sysdeps-search.
Use <bits/wordsize.h> instead of <sizes.h> to determine PTR_SIZE_STR.
* sysdeps/gnu/siglist.h: New file, contents from linux version.
Add entry for SIGLOST protected by #ifdef.
* sysdeps/unix/sysv/linux/siglist.h: Just #include that file,
and define OLD_SIGLIST_SIZE_STR.
* sysdeps/mach/hurd/siglist.h: New file, likewise.
