ENDBR64 is added to the special TLSDESC entry, which is similar to the
PLT0 entry, in the x86-64 lazy procedure linkage table to support Intel
CET.  The NaCl PLT is different from the normal PLT.  This patch adds
plt_tlsdesc_entry, plt_tlsdesc_entry_size, plt_tlsdesc_got1_offset,
plt_tlsdesc_got2_offset, plt_tlsdesc_got1_insn_end and
plt_tlsdesc_got2_insn_end to elf_x86_lazy_plt_layout to support both
normal and NaCl TLSDESC entries.  This fixed

FAIL: TLS descriptor -fpic -shared transitions

for x86_64-nacl.

	* elf32-i386.c (elf_i386_lazy_plt): Add plt_tlsdesc_entry,
	plt_tlsdesc_entry_size, plt_tlsdesc_got1_offset,
	plt_tlsdesc_got2_offset, plt_tlsdesc_got1_insn_end and
	plt_tlsdesc_got2_insn_end for TLSDESC entry.
	(elf_i386_lazy_ibt_plt): Likewise.
	(elf_i386_nacl_plt): Likewise.
	* elf64-x86-64.c (tlsdesc_plt_entry): Moved and renamed to ...
	(elf_x86_64_tlsdesc_plt_entry): This.
	(elf_x86_64_lazy_plt): Add plt_tlsdesc_entry,
	plt_tlsdesc_entry_size, plt_tlsdesc_got1_offset,
	plt_tlsdesc_got2_offset, plt_tlsdesc_got1_insn_end and
	plt_tlsdesc_got2_insn_end for TLSDESC entry.
	(elf_x86_64_lazy_bnd_plt): Likewise.
	(elf_x86_64_lazy_ibt_plt): Likewise.
	(elf_x32_lazy_ibt_plt): Likewise.
	(elf_x86_64_nacl_plt): Likewise.
	(elf_x86_64_finish_dynamic_sections): Use plt_tlsdesc_entry,
	plt_tlsdesc_entry_size, plt_tlsdesc_got1_offset,
	plt_tlsdesc_got2_offset, plt_tlsdesc_got1_insn_end and
	plt_tlsdesc_got2_insn_end to update TLSDESC entry.
	* elfxx-x86.h (elf_x86_lazy_plt_layout): Update comments.
	Add plt_tlsdesc_entry, plt_tlsdesc_entry_size,
	plt_tlsdesc_got1_offset, plt_tlsdesc_got2_offset,
	plt_tlsdesc_got1_insn_end and plt_tlsdesc_got2_insn_end.
	(elf_x86_non_lazy_plt_layout): Update comments.
	(elf_x86_plt_layout): Likewise.