Dumb bug in weak support

[Jeffrey A Law]

Linux strcmp blows up if one of the arguments to strcmp is a null pointer.
This fixes a bootstrap failure on ppc-linux.

        * varasm.c (remove_from_pending_weak_list): Verify t->name
        is non-NULL before passing it to strcmp.

Index: varasm.c
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/varasm.c,v
retrieving revision 1.59.4.3
retrieving revision 1.59.4.4
diff -c -r1.59.4.3 -r1.59.4.4
*** varasm.c	1999/06/07 19:46:11	1.59.4.3
--- varasm.c	1999/06/09 12:13:49	1.59.4.4
***************
*** 4388,4394 ****
        struct weak_syms *t;
        for (t = weak_decls; t; t = t->next)
  	{
! 	  if (strcmp (name, t->name) == 0)
  	    t->name = NULL;
  	}
      }
--- 4388,4394 ----
        struct weak_syms *t;
        for (t = weak_decls; t; t = t->next)
  	{
! 	  if (t->name && strcmp (name, t->name) == 0)
  	    t->name = NULL;
  	}
      }