[patch i386]: Add for win32 targets pre-prologue profiling feature

[Gerald Pfeifer]

On Thu, 15 Jul 2010, Kai Tietz wrote:
> 	* doc/invoke.texi (mfentry): Add documentation.

+Note: On x86 architectures the attribute @code{ms_hook_prologue}               
+isn't possible at the moment for @option{-mfentry} and @option{-pg}.

How about: "...is not supported for...at the moment."?

And if you could add an item to http://gcc.gnu.org/gcc-4.6/changes.html
when this goes in, that would be good.

Gerald