Support in ld for Hurd on Alpha

[Fila Kolodny]

The following patch should allow support in ld for Hurd running on Alpha.
*** gas-960827/ld/configure.tgt	Tue Aug 13 18:37:47 1996
--- mygas/ld/configure.tgt	Tue Aug 27 12:40:44 1996
*************** alpha-*-linux*)		targ_emul=elf64alpha ta
*** 133,138 ****
--- 133,139 ----
  			tdir_alpha=`echo ${targ_alias} | sed -e 's/linux/linuxecoff/'`
  			;;
  alpha-*-osf*)		targ_emul=alpha ;;
+ alpha-*-gnu*)		targ_emul=elf64alpha ;;
  alpha-*-netware*)	targ_emul=alpha ;;
  z8k-*-coff) 		targ_emul=z8002; targ_extra_emuls=z8001 ;;
  ns32k-pc532-mach* | ns32k-pc532-ux*)	targ_emul=pc532macha ;;