Add support for the Win32 hook prologue (try 3)

[Stefan Dösinger]

Am Saturday 12 September 2009 00:49:00 schrieb Richard Henderson:
> Your new hook will have to do the work of both ASM_OUTPUT_ALIGN and the
> subsequent call to ASM_OUTPUT_MAX_SKIP_ALIGN at the same time.  So
> you'll have to rearrange the code in assemble_start_function a bit.
What stops me from dumping the 5 NOPs, then going through the usual 
ASM_OUTPUT_ALIGN and ASM_OUTPUT_MAX_SKIP_ALIGN? What extra logic has to be 
applied that 3 separate functions can't do?