x86: Keep the unused _GLOBAL_OFFSET_TABLE_ for Solaris

x86: Keep the unused _GLOBAL_OFFSET_TABLE_ for Solaris

Solaris requires to keep _GLOBAL_OFFSET_TABLE_ even if it isn't used.
This patch detects Solaris target and keeps _GLOBAL_OFFSET_TABLE_ for
Solaris.

	* elf32-i386.c (elf32_i386_copy_solaris_special_section_fields):
	New prototype.
	(elf_i386_link_setup_gnu_properties): Set need_global_offset_table
	for Solaris.
	* elf64-x86-64.c (elf64_x86_64_copy_solaris_special_section_fields):
	New prototype.
	(elf_x86_64_link_setup_gnu_properties): Set
	need_global_offset_table for Solaris.
	* elfxx-x86.c (_bfd_x86_elf_size_dynamic_sections): Keep the
	unused _GLOBAL_OFFSET_TABLE_ for Solaris.
	(_bfd_x86_elf_link_setup_gnu_properties): Copy
	need_global_offset_table.
	* elfxx-x86.h (elf_x86_link_hash_table): Add
	need_global_offset_table.
	(elf_x86_init_table): Likewise.