Add BPF jset instruction support to Minijail.

First step is to add support for the actual BPF instruction.
Next step is to parse this in the policy files and use the functions
introduced by this CL.

BUG=chromium-os:36848
TEST=syscall_filter_unittest

Change-Id: I172598e63413506f190ae6b4b07ae63e1198f44c
Reviewed-on: https://gerrit.chromium.org/gerrit/39018
Reviewed-by: Kees Cook <keescook@chromium.org>
Commit-Ready: Jorge Lucangeli Obes <jorgelo@chromium.org>
Tested-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
3 files changed