boring syscall stuff. It has two phases now: The first one
(gensyscallinfos) parses syscalls.h and generates a source file containing
all the required information. This file is compiled and linked to
gensyscalls, which generates the actual output files.
Added to the build.
git-svn-id: file:///srv/svn/repos/haiku/trunk/current@8697 a95241bf-73f2-0310-859d-f6bbb57e9c96