PowerPC non-PIC to PIC editing for protected var access

PowerPC non-PIC to PIC editing for protected var access

This is a linker-only solution to the incompatibility between shared
library protected visibility variables and using .dynbss and copy
relocs for non-PIC access to shared library variables.

bfd/
	* elf32-ppc.c (struct ppc_elf_link_hash_entry): Add has_addr16_ha
	and has_addr16_lo.  Make has_sda_refs a bitfield.
	(ppc_elf_check_relocs): Set new flags.
	(ppc_elf_link_hash_table_create): Update default_params.
	(ppc_elf_adjust_dynamic_symbol): Clear protected_def in cases
	where we won't be making .dynbss entries or editing code.  Set
	params->pic_fixup when we'll edit code for protected var access.
	(allocate_dynrelocs): Allocate got entry for edited code and
	discard dyn_relocs.
	(struct ppc_elf_relax_info): Add picfixup_size.
	(ppc_elf_relax_section): Rename struct one_fixup to struct
	one_branch_fixup.  Rename fixups to branch_fixups.  Size space for
	pic fixups.
	(ppc_elf_relocate_section): Edit non-PIC accessing protected
	visibility variables to PIC.  Don't emit dyn_relocs for code
	we've edited.
	* elf32-ppc.h (struct ppc_elf_params): Add pic_fixup.
ld/
	* emultempl/ppc32elf.em: Handle --no-pic-fixup.
	(params): Init new field.
	(ppc_before_allocation): Enable relaxation for pic_fixup.