crosstest target missing dependency on idl headers

[John Klehm]

Hello,

Just thought I'd mention that the crosstest target is missing dependencies
on headers generated from .idl files.  The ones that come up for me are
tmarshal.h(oleaut32) and server.h (rpcrt4).   Thanks to Hans Leidekker for
helping me find my way on this.

So as of right now here is how the process works:
> From a clean source dir:

./configure
make crosstest   =>  error: missing tmarshal.h
make -C dlls/oleaut32/tests => errors out as well but it builds tmarshal.h
make crosstest => error: missing server.h
make -C dlls/rpcrt4/tests => errors out as well but builds server.h
make crosstest => suceeds

Maybe this will be helpful to someone else who found it slightly confusing.

John