[patch]: For mingw and cygwin targets allow second make of libgcc

[Paolo Bonzini]

Kai Tietz wrote:
> Hi,
> 
> as I noticed while testing the patch about shared version of libgcc 
> introduced an minor issue for mingw and cygwin targets. The build will 
> fail, if you try to do a second attempt to link/compile libgcc. This is 
> reasoned by a generation of a symbolic link, without checking if this 
> already exists.
> 
> ChangeLog
> 
> 2008-11-18  Kai Tietz  <kai.tietz@onevision.com>
> 
>         * config/i386/t-cygming (SHLIB_LINK): Make sure that 
> $(SHLIB_MAP).def
>         is removed before trying to do a symbol link.

"$(LN_S) -f" should work instead and is preapproved.

Paolo