aarch64: Add support for GNU indirect functions.

Add support for STT_GNU_IFUNC symbols to the AArch64 bfd backend. The tests
are ported from the ld-ifunc tests but are enabled for cross builds so can
be run easily without hardware or a simulator.

bfd/ChangeLog:

2013-06-07  Will Newton  <will.newton@linaro.org>

	* configure: Regenerate.
	* configure.in: Build elf-ifunc.o for AArch64.
	* elf64-aarch64.c: Include objalloc.h.
	(elf64_aarch64_howto_dynrelocs): Add R_AARCH64_IRELATIVE howto.
	(struct elf64_aarch64_link_hash_table): Add members for handling
	R_AARCH64_IRELATIVE relocations.
	(elf_aarch64_local_htab_hash): New function.
	(elf_aarch64_local_htab_eq): New function.
	(elf_aarch64_get_local_sym_hash): New function.
	(elf64_aarch64_link_hash_table_create): Initialize local STT_GNU_IFUNC
	symbol hash.
	(elf64_aarch64_hash_table_free): Free local STT_GNU_IFUNC symbol hash.
	(elf64_aarch64_final_link_relocate): Add sym argument.  Add support
	for handling STT_GNU_IFUNC symbols.
	(elf64_aarch64_gc_sweep_hook): Add support for garbage collecting
	references to STT_GNU_IFUNC symbols.
	(elf64_aarch64_adjust_dynamic_symbol): Add support for handling
	STT_GNU_IFUNC symbols.
	(elf64_aarch64_check_relocs): Add support for handling STT_GNU_IFUNC
	symbols.  Ensure we don't increase plt.refcount from -1 to 0.
	(elf64_aarch64_post_process_headers): Call _bfd_elf_set_osabi.
	(elf64_aarch64_is_function_type): Remove function.
	(elf64_aarch64_allocate_dynrelocs): Call
	_bfd_elf_allocate_ifunc_dyn_relocs for STT_GNU_IFUNC symbols.
	(elf_aarch64_allocate_local_dynrelocs): New function.
	(elf64_aarch64_size_dynamic_sections): Call
	elf_aarch64_allocate_local_dynrelocs.  Initialize next_irelative_index.
	(elf64_aarch64_create_small_pltn_entry): Add info argument.
	Add support for creating .iplt entries for STT_GNU_IFUNC symbols.
	(elf64_aarch64_finish_dynamic_symbol): Add support for handling
	STT_GNU_IFUNC symbols and .iplt.
	(elf_aarch64_finish_local_dynamic_symbol): New function.
	(elf64_aarch64_finish_dynamic_sections): Call
	elf_aarch64_finish_local_dynamic_symbol.
	(elf64_aarch64_add_symbol_hook): New function.

include/elf/ChangeLog:

2013-06-07  Will Newton  <will.newton@linaro.org>

	* aarch64.h: Add R_AARCH64_IRELATIVE reloc.

ld/ChangeLog:

2013-06-07  Will Newton  <will.newton@linaro.org>

	* emulparams/aarch64elf.sh: Add IREL_IN_PLT.

ld/testsuite/ChangeLog:

2013-06-07  Will Newton  <will.newton@linaro.org>

	* ld-ifunc/ifunc.exp: Enable ifunc tests for AArch64.
	* ld-aarch64/aarch64-elf.exp: Add ifunc tests.
	* ld-aarch64/ifunc-1-local.d: New file.
	* ld-aarch64/ifunc-1-local.s: Likewise.
	* ld-aarch64/ifunc-1.d: Likewise.
	* ld-aarch64/ifunc-1.s: Likewise.
	* ld-aarch64/ifunc-10.d: Likewise.
	* ld-aarch64/ifunc-10.s: Likewise.
	* ld-aarch64/ifunc-11.d: Likewise.
	* ld-aarch64/ifunc-11.s: Likewise.
	* ld-aarch64/ifunc-12.d: Likewise.
	* ld-aarch64/ifunc-12.s: Likewise.
	* ld-aarch64/ifunc-13.d: Likewise.
	* ld-aarch64/ifunc-13a.s: Likewise.
	* ld-aarch64/ifunc-13b.s: Likewise.
	* ld-aarch64/ifunc-14a.d: Likewise.
	* ld-aarch64/ifunc-14a.s: Likewise.
	* ld-aarch64/ifunc-14b.d: Likewise.
	* ld-aarch64/ifunc-14b.s: Likewise.
	* ld-aarch64/ifunc-14c.d: Likewise.
	* ld-aarch64/ifunc-14c.s: Likewise.
	* ld-aarch64/ifunc-14d.d: Likewise.
	* ld-aarch64/ifunc-14e.d: Likewise.
	* ld-aarch64/ifunc-14f.d: Likewise.
	* ld-aarch64/ifunc-15.d: Likewise.
	* ld-aarch64/ifunc-15.s: Likewise.
	* ld-aarch64/ifunc-16.d: Likewise.
	* ld-aarch64/ifunc-16.s: Likewise.
	* ld-aarch64/ifunc-17a.d: Likewise.
	* ld-aarch64/ifunc-17a.s: Likewise.
	* ld-aarch64/ifunc-17b.d: Likewise.
	* ld-aarch64/ifunc-17b.s: Likewise.
	* ld-aarch64/ifunc-18a.d: Likewise.
	* ld-aarch64/ifunc-18a.s: Likewise.
	* ld-aarch64/ifunc-18b.d: Likewise.
	* ld-aarch64/ifunc-18b.s: Likewise.
	* ld-aarch64/ifunc-19a.d: Likewise.
	* ld-aarch64/ifunc-19a.s: Likewise.
	* ld-aarch64/ifunc-19b.d: Likewise.
	* ld-aarch64/ifunc-19b.s: Likewise.
	* ld-aarch64/ifunc-2-local.d: Likewise.
	* ld-aarch64/ifunc-2-local.s: Likewise.
	* ld-aarch64/ifunc-2.d: Likewise.
	* ld-aarch64/ifunc-2.s: Likewise.
	* ld-aarch64/ifunc-20.d: Likewise.
	* ld-aarch64/ifunc-20.s: Likewise.
	* ld-aarch64/ifunc-3.s: Likewise.
	* ld-aarch64/ifunc-3a.d: Likewise.
	* ld-aarch64/ifunc-3b.d: Likewise.
	* ld-aarch64/ifunc-4.d: Likewise.
	* ld-aarch64/ifunc-4.s: Likewise.
	* ld-aarch64/ifunc-4a.d: Likewise.
	* ld-aarch64/ifunc-5-local.s: Likewise.
	* ld-aarch64/ifunc-5.s: Likewise.
	* ld-aarch64/ifunc-5a-local.d: Likewise.
	* ld-aarch64/ifunc-5a.d: Likewise.
	* ld-aarch64/ifunc-5b-local.d: Likewise.
	* ld-aarch64/ifunc-5b.d: Likewise.
	* ld-aarch64/ifunc-5r-local.d: Likewise.
	* ld-aarch64/ifunc-6.s: Likewise.
	* ld-aarch64/ifunc-6a.d: Likewise.
	* ld-aarch64/ifunc-6b.d: Likewise.
	* ld-aarch64/ifunc-7.s: Likewise.
	* ld-aarch64/ifunc-7a.d: Likewise.
	* ld-aarch64/ifunc-7b.d: Likewise.
	* ld-aarch64/ifunc-8.d: Likewise.
	* ld-aarch64/ifunc-8a.s: Likewise.
	* ld-aarch64/ifunc-8b.s: Likewise.
	* ld-aarch64/ifunc-9.d: Likewise.
	* ld-aarch64/ifunc-9.s: Likewise.