netbsd-elf.h (LINK_SPEC): Define as NETBSD_LINK_SPEC_ELF.

* config/i386/netbsd-elf.h (LINK_SPEC): Define as
NETBSD_LINK_SPEC_ELF.
(SUBTARGET_EXTRA_SPECS): Add netbsd_entry_point.
(NETBSD_ENTRY_POINT): Define.
* config/i386/netbsd64.h (LINK_SPEC): Use %(netbsd_link_spec).
(SUBTARGET_EXTRA_SPECS): Add netbsd_link_spec and
netbsd_entry_point.
(NETBSD_ENTRY_POINT): Define.

From-SVN: r54362