Get ld -x -r to handle a.out set symbols correctly.

	Get ld -x -r to handle a.out set symbols correctly.
	* aoutx.h (adjust_o_magic): If the .bss VMA was set outside of
	BFD, pad the .data section up to the VMA of the .bss section.
	(aout_link_add_symbols): If a set symbol does not get modified,
	treat it as a local symbol.
	(aout_link_write_symbols): Set the value of set symbols
	correctly.  Don't discard set symbols even if discarding local
	symbols.
	(aout_link_write_other_symbol): Don't abort on bfd_link_hash_new,
	since it can now happen for set symbols.