* emulparams/elf_x86_64.sh (LARGE_BSS_AFTER_BSS): Define.
	* emulparams/elf32_x86_64.sh: Likewise.
	* emulparams/elf_k1om.sh: Likewise.
	* emulparams/elf_l1om.sh: Likewise.
	* scripttempl/elf.sc (LARGE_BSS): Define rather than appending to
	OTHER_BSS_SECTIONS.  Substitute in script.