gold aarch64 patch to enable linking hello_wolrd.

elfcpp/ChangeLog:
2014-08-08  Han Shen  <shenhan@google.com>

	* aarch64.h (withdrawn): Replaced with R_AARCH64_withdrawn.

2014-08-08  Jing Yu  <jingyu@google.com>
	    Han Shen  <shenhan@google.com>

	* Makefile.am (HFILES): Add aarch64-reloc-property.h.
	(DEFFILES): add aarch64-reloc.def.
	(TARGETSOURCES): Add aarch64-reloc-property.cc.
	(ALL_TARGETOBJS): Add aarch64-reloc-property.$(OBJEXT).
	* Makefile.in: Regenerate.
	* aarch64-reloc-property.cc: New file.
	* aarch64-reloc-property.h: New file.
	* aarch64-reloc.def: New file.
	* aarch64.cc: Include aarch64-reloc-property.h. Replace spaces
	with tab to make the format consistent.
	(Output_data_got_aarch64::symbol_table_): New method.
	(Target_aarch64::do_plt_address_for_global): New method.
	(Target_aarch64::do_plt_address_for_local): New method.
	(Target_aarch64::do_select_as_default_target): New method.
	(Target_aarch64::do_make_data_plt): New method.
	(Target_aarch64::make_data_plt): New method.
	(Output_data_plt_aarch64::has_irelative_section): New method.
	(Output_data_plt_aarch64::address_for_global): New method.
	(Output_data_plt_aarch64::address_for_local): New method.
	(Output_data_plt_aarch64::irelative_rel_): New parameter.
	(Output_data_plt_aarch64::add_entry): Implement contents.
	(Output_data_plt_aarch64::set_final_data_size): Fix typo.
	(Output_data_plt_aarch64::do_write): Remove useless got_base. Set
	the got_pov entry to plt0.
	(Output_data_plt_aarch64_standard::do_fill_first_plt_entry):
	Implement contents.
	(Output_data_plt_aarch64_standard::do_fill_plt_entry): Implement.
	(AArch64_howto): New struct.
	(aarch64_howto[]): New static const array.
	(AArch64_relocate_functions): New class.
	(Target_aarch64::Scan::get_reference_flags): Remove method.
	(Target_aarch64::Scan::local): Implement to support a few relocations.
	(Target_aarch64::Scan::global): Implement to support a few relocations.
	(Target_aarch64::make_plt_section): Implement contents.
	(Target_aarch64::make_plt_entry): Implement contents.
	(Target_aarch64::do_finalize_sections): Implement contents.
	(Target_aarch64::Relocate::relocate): Implement a few relocations.
	(Target_aarch64::relocate_section): Implement contents.