Handle the sethostname system call. BZ#311922.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13458 a5019735-40e9-0310-863c-91ae7b9d1cf9
Add support for open_by_handle_at and fix name_to_handle_at
to check the file handle argument correctly. BZ#316761.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13459 a5019735-40e9-0310-863c-91ae7b9d1cf9