[patch targets]: Add support of ms_hook_prologue for x64 architecture

[Jack Howarth]

On Thu, Jul 08, 2010 at 01:14:14PM +0200, Kai Tietz wrote:
> Hello,
> 
> I reworked my initial patch (which is reverted) and now I am using the 
> approach to introduce for function-label emitting the new macro 
> ASM_OUTPUT_FUNCTION_LABEL, which can be overriden by architectures on 
> demand.
> 

Kai,
   This one looks more hopeful. It appears to bootstrap cleanly c/c++
on x86_64-apple-darwin10. I still need to do a full build against all
of the supported languages on darwin and a regression test though.
              Jack