Add support for non-ELF targets to check their relocs.

Add support for non-ELF targets to check their relocs.

bfd	* aout-adobe.c: Use _bfd_generic_link_check_relocs.
	* aout-target.h: Likewise.
	* aout-tic30.c: Likewise.
	* binary.c: Likewise.
	* bout.c: Likewise.
	* coff-alpha.c: Likewise.
	* coff-rs6000.c: Likewise.
	* coff64-rs6000.c: Likewise.
	* coffcode.h: Likewise.
	* i386msdos.c: Likewise.
	* i386os9k.c: Likewise.
	* ieee.c: Likewise.
	* ihex.c: Likewise.
	* libbfd-in.h: Likewise.
	* libecoff.h: Likewise.
	* mach-o-target.c: Likewise.
	* mmo.c: Likewise.
	* nlm-target.h: Likewise.
	* oasys.c: Likewise.
	* pef.c: Likewise.
	* plugin.c: Likewise.
	* ppcboot.c: Likewise.
	* som.c: Likewise.
	* srec.c: Likewise.
	* tekhex.c: Likewise.
	* versados.c: Likewise.
	* vms-alpha.c: Likewise.
	* xsym.c: Likewise.
	* elfxx-target.h: Use _bfd_elf_link_check_relocs.
	* linker.c (bfd_link_check_relocs): New function.
	(_bfd_generic_link_check_relocs): New function.
	* targets.c (BFD_JUMP_TABLE_LINK): Add initialization of
	_bfd_link_check_relocs field.
	(struct bfd_target)L Add _bfd_link_check_relocs field.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Regenerate.

ld	* ldlang.c (lang_check_relocs): Use bfd_link_check_relocs in
	prefernce to _bfd_elf_link_check_relocs.  Drop test for ELF
	targets.  Do not stop the checks when problems are encountered.

include	* bfdlink.h: Add prototype for bfd_link_check_relocs.