Add wrappers for ExitProcess, TerminateProcess

[Charles Wilson]

Corinna Vinschen wrote:
> Looks good to me.  Let's wait for Chris, though.  I have just one question.

OK.

> Shouldn't exit_process be marked with attribute(noreturn) or is the
> optimizing effect negligible?

It is already marked noreturn, in the declaration at the top of the
file.  I got an error when I marked the definition that way --
apparently gcc4 doesn't like that:

/usr/src/devel/kernel/src/winsup/cygwin/external.cc:181: error:
attributes are not allowed on a function-definition

I even tried to include the attribute on a (forward) declaration AND the
definition, but I got the same error.  The only thing that works is the
way I've already done it: apply the attribute to the (forward)
declaration, but not the definition.

--
Chuck