PR ld/4424

	PR ld/4424
	* config.bfd (targ_selvecs): Add bfd_elf64_alpha_vec for
	alpha/FreeBSD.  Add bfd_elf64_sparc_vec for sparc64/FreeBSD.
	Add bfd_elf32_i386_vec and bfd_efi_app_ia32_vec for i386/FreeBSD.
	(targ64_selvecs): Set for i386/FreeBSD.
	* elf-bfd.h (elf_backend_data): Add relocs_compatible.
	(_bfd_elf_default_relocs_compatible): Declare.
	(_bfd_elf_relocs_compatible): Declare.
	* elfxx-target.h (elf_backend_relocs_compatible): Define.
	(elfNN_bed): Init new relocs_compatible field.
	* elflink.c (_bfd_elf_default_relocs_compatible): New function.
	(_bfd_elf_relocs_compatible): New function.
	(elf_link_add_object_symbols): Call bed->relocs_compatible.
	* elf32-i386.c (elf_backend_relocs_compatible): Define.
	* elf64-alpha.c: Likewise.
	* elf64-sparc.c: Likewise.
	* elf64-x86-64.c: Likewise.