Copy relocations against protected symbols

Copy relocs are used in a scheme to avoid dynamic text relocations in
non-PIC executables that refer to variables defined in shared
libraries.  The idea is to have the linker define any such variable in
the executable, with a copy reloc copying the initial value, then have
both the executable and shared library refer to the executable copy.
If the shared library defines the variable as protected then we have
two copies of the variable being used.

	PR 15228
	* elflink.c (_bfd_elf_adjust_dynamic_copy): Add "info" param.
	Error on copy relocs against protected symbols.
	(elf_merge_st_other): Set h->protected_def.
	* elf-bfd.h (struct elf_link_hash_entry): Add "protected_def".
	(_bfd_elf_adjust_dynamic_copy): Update prototype.
	* elf-m10300.c (_bfd_mn10300_elf_adjust_dynamic_symbol): Update
	_bfd_elf_adjust_dynamic_copy call.
	* elf32-arm.c (elf32_arm_adjust_dynamic_symbol): Likewise.
	* elf32-cr16.c (_bfd_cr16_elf_adjust_dynamic_symbol): Likewise.
	* elf32-cris.c (elf_cris_adjust_dynamic_symbol): Likewise.
	* elf32-hppa.c (elf32_hppa_adjust_dynamic_symbol): Likewise.
	* elf32-i370.c (i370_elf_adjust_dynamic_symbol): Likewise.
	* elf32-i386.c (elf_i386_adjust_dynamic_symbol): Likewise.
	* elf32-lm32.c (lm32_elf_adjust_dynamic_symbol): Likewise.
	* elf32-m32r.c (m32r_elf_adjust_dynamic_symbol): Likewise.
	* elf32-m68k.c (elf_m68k_adjust_dynamic_symbol): Likewise.
	* elf32-metag.c (elf_metag_adjust_dynamic_symbol): Likewise.
	* elf32-or1k.c (or1k_elf_adjust_dynamic_symbol): Likewise.
	* elf32-ppc.c (ppc_elf_adjust_dynamic_symbol): Likewise.
	* elf32-s390.c (elf_s390_adjust_dynamic_symbol): Likewise.
	* elf32-sh.c (sh_elf_adjust_dynamic_symbol): Likewise.
	* elf32-tic6x.c (elf32_tic6x_adjust_dynamic_symbol): Likewise.
	* elf32-tilepro.c (tilepro_elf_adjust_dynamic_symbol): Likewise.
	* elf32-vax.c (elf_vax_adjust_dynamic_symbol): Likewise.
	* elf64-ppc.c (ppc64_elf_adjust_dynamic_symbol): Likewise.
	* elf64-s390.c (elf_s390_adjust_dynamic_symbol): Likewise.
	* elf64-sh64.c (sh64_elf64_adjust_dynamic_symbol): Likewise.
	* elf64-x86-64.c (elf_x86_64_adjust_dynamic_symbol): Likewise.
	* elfnn-aarch64.c (elfNN_aarch64_adjust_dynamic_symbol): Likewise.
	* elfxx-mips.c (_bfd_mips_elf_adjust_dynamic_symbol): Likewise.
	* elfxx-sparc.c (_bfd_sparc_elf_adjust_dynamic_symbol): Likewise.
	* elfxx-tilegx.c (tilegx_elf_adjust_dynamic_symbol): Likewise.