MSVC hook function prologue

[Ross Ridge]

Paolo Bonzini writes:
>Are there non-Microsoft DLLs that expect to be hooked this way?  If
>so, I think the patch is interesting for gcc independent of whether it
>is useful for Wine.

Stefan Dösinger writes:
>I haven't seen any so far. ...

If this patch is essentially only for one application, maybe the idea
of implementing a more generally useful naked attribute would be the
way to go.  I implemented a naked attribute in my private sources to
do something similar, although supporting hookable prologues was just
a small part of its more general use in supporting an assembler based API.

					Ross Ridge