gold/ld: enable gnu hash by default
    
    Glibc first added .gnu.hash support to glibc-2.5 (released 29 Sep 2006),
    and gold was first released after that.  Let's default the gnu hash style
    to the new "gnu" rather than the classic sysv.
    
    gold/:
    2012-02-03  Mike Frysinger  <vapier@gentoo.org>
    
    	* options.h (General_options): Change default to gnu for hash_style.