x86: Add _bfd_x86_elf_size_dynamic_sections

x86: Add _bfd_x86_elf_size_dynamic_sections

elf_i386_size_dynamic_sections and elf_x86_64_size_dynamic_sections are
very similar, except for the followings:

1. elf_i386_size_dynamic_sections checks GOT_TLS_IE and GOT_TLS_IE_BOTH.
elf_x86_64_size_dynamic_sections checks only GOT_TLS_IE.  Since
GOT_TLS_IE_BOTH is never true for x86-64, it is OK to check GOT_TLS_IE
for both i386 and x86-64.
2, x86-64 sets tlsdesc_plt, but i386 doesn't.  We set tlsdesc_plt only
if target_id == X86_64_ELF_DATA.
3. x86-64 has

	  if (s != htab->elf.srelplt)
	    s->reloc_count = 0;

and i386 has

	  s->reloc_count = 0;

i386 did have

	  if (s != htab->srelplt)
	    s->reloc_count = 0;

in the original commit:

commit 67a4f2b710581acc83afecff55424af285ecbc28
Author: Alexandre Oliva <aoliva@redhat.com>
Date:   Wed Jan 18 21:07:51 2006 +0000

But it was removed by

commit 5ae0bfb60a576344d7f701605346282c1144499e
Author: Richard Sandiford <rdsandiford@googlemail.com>
Date:   Tue Feb 28 07:16:12 2006 +0000

    bfd/
            * elf32-i386.c (elf_i386_link_hash_table): Add next_tls_desc_index.
            (elf_i386_link_hash_table_create): Initialize it.
            (elf_i386_compute_jump_table_size): Use it instead of
            srelplt->reloc_count.
            (allocate_dynrelocs): Likewise.
            (elf_i386_size_dynamic_sections): Likewise.
            (elf_i386_relocate_section): Likewise.

A later commit:

commit e1f987424b7b3f5ac63a2a6ae044a202a44b8ff8
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Fri Oct 21 15:13:37 2011 +0000

    Put IRELATIVE relocations after JUMP_SLOT.

    bfd/

    2011-10-21  H.J. Lu  <hongjiu.lu@intel.com>

            PR ld/13302
            * elf32-i386.c (elf_i386_link_hash_table): Add next_jump_slot_index
            and next_irelative_index.
            (elf_i386_link_hash_table_create): Initialize next_jump_slot_index
            and next_irelative_index.
            (elf_i386_allocate_dynrelocs): Increment reloc_count instead of
            next_tls_desc_index.
            (elf_i386_size_dynamic_sections): Set next_tls_desc_index and
            next_irelative_index from reloc_count.
            (elf_i386_finish_dynamic_symbol): Put R_386_IRELATIVE after
            R_386_JUMP_SLOT.

changed it back to use reloc_count again. So it is correct to use

	  if (s != htab->elf.srelplt)
	    s->reloc_count = 0;

for both i386 and x86-64 now.
4. i386 and x86-64 use different DT_XXXs.  They are handled by adding
them to elf_x86_link_hash_table.

With these changes, we can share _bfd_x86_elf_size_dynamic_sections in
elf32-i386.c and elf64-x86-64.c.

	* elf32-i386.c (elf_i386_convert_load): Renamed to ...
	(_bfd_i386_elf_convert_load): This.  Remove static.
	(elf_i386_size_dynamic_sections): Removed.
	(elf_backend_size_dynamic_sections): Likewise.
	* elf64-x86-64.c (elf_x86_64_convert_load): Renamed to ...
	(_bfd_x86_64_elf_convert_load): This.  Remove static.
	(elf_x86_64_size_dynamic_sections): Removed.
	(elf_backend_size_dynamic_sections): Likewise.
	* elfxx-x86.c (_bfd_x86_elf_allocate_dynrelocs): Renamed to ...
	(elf_x86_allocate_dynrelocs): This.  Make it static.
	(_bfd_x86_elf_allocate_local_dynrelocs): Renamed to ...
	(elf_x86_allocate_local_dynreloc): This.  Make it static.
	(elf_i386_is_reloc_section): New function.
	(elf_x86_64_is_reloc_section): Likewise.
	(_bfd_x86_elf_link_hash_table_create): Initialize convert_load,
	is_reloc_section, dt_reloc, dt_reloc_sz and dt_reloc_ent.
	Rearrange got_entry_size initialization.
	(_bfd_x86_elf_size_dynamic_sections): New function.
	* elfxx-x86.h (elf_x86_link_hash_table): Add convert_load,
	is_reloc_section, dt_reloc, dt_reloc_sz and dt_reloc_ent.
	(_bfd_i386_elf_convert_load): New.
	(_bfd_x86_64_elf_convert_load): Likewise.
	(_bfd_x86_elf_size_dynamic_sections): Likewise.
	(elf_backend_size_dynamic_sections): Likewise.
	(_bfd_x86_elf_allocate_dynrelocs): Removed.
	(_bfd_x86_elf_allocate_local_dynrelocs): Likewise.