* copy-relocs.h: New file.
	* reloc.cc: Remove Copy_relocs code.
	* reloc.h: Likewise.
	* reloc-types.h (struct Reloc_types) [both versions]: Add
	get_reloc_addend_noerror.
	* output.h (class Output_data_reloc<elfcpp::SHT_REL>): Add
	variants of add_global which take an addend which must be zero.
	* i386.cc: Include "copy-relocs.h".
	(class Target_i386): Change type of copy_relocs_ to variable,
	update initializer.
	(Target_i386::copy_reloc): Rewrite to pass to Copy_relocs class.
	Change all callers.
	(Target_i386::do_finalize_sections): Change handling of
	copy_relocs_.
	* sparc.cc: Include "copy-relocs.h".
	(class Target_sparc): Change type of copy_relocs_ to variable,
	update initializer.
	(Target_sparc::copy_reloc): Rewrite to pass to Copy_relocs class.
	Change all callers.
	(Target_sparc::do_finalize_sections): Change handling of
	copy_relocs_.
	* x86_64.cc: Include "copy-relocs.h".
	(class Target_x86_64): Change type of copy_relocs_ to variable,
	update initializer.
	(Target_x86_64::copy_reloc): Rewrite to pass to Copy_relocs
	class.  Change all callers.
	(Target_x86_64::do_finalize_sections): Change handling of
	copy_relocs_.
	* Makefile.am (CCFILES): Add copy-relocs.cc.
	(HFILES): Add copy-relocs.h.