pointed out by Klaus Klein (original idea was that it should hold at least
the pathname ...); instead, let the ELF and a.out backends allocate memory
for the link command, and get rid of the fixed size buffer altogether
updated for the symtab support for a.out (non for ELF yet) and other cleanup
by myself. should work on the alpha as well as other ELF ports...
remove the ld(1) output by default, rather than leaving little binary turds
across the filesystem...
