Patch: Make PE-CFF "weak externals" behaviour consistent between GNU and MS linker.

[Aaron W. LaFramboise]

Danny Smith wrote:

> This patch changes the comment in bfd/cofflink.c to reflect reality and
> makes gas produce object files with IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY
> characteristic set.

FWIW, since I was the one who wrote this comment, I agree that this 
patch is the right thing to do.

I had intended to look at this myself, but unfortunately I ran out of time.

Aaron W. LaFramboise