* config/unix.exp: Use nm.new, not nm, from newly built tree.
* binutils.all/objdump.exp: Add more wildcards to list of
single-letter options in pattern for usage message.
* binutils.all/nm.exp: Deleted debug-symbols test, since it only
works for a.out/stabs systems. Fixed regexps to make underscores
optional, since some C compilers don't prepend them. Deleted
check for foo.o symbol, since again some systems don't generate
it.
