provide general raw_syscall() interface?

_From [derek.br...@gmail.com](https://code.google.com/u/117968039472581148324/) on August 13, 2009 13:11:30_

Our general philosophy has been to provide platform-independent utilities.
But advanced clients sometimes need to make raw system calls.
Previously we assumed that if they were advanced enough to know what call
to make they could do it themselves: and that's what my clients have done,
whether with Nt wrappers calls on Windows or inline asm int80 on Linux.

On reason to provide an API routine is if DR then acts on any
memory/control changes that affect its operations. Or, we could provide it
for convenience and heavily document it as "at own risk". I suppose I'm
not convinced it's a good idea to have in the API

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=199_