Changes to support ELF strip and objcopy on dynamically linked

	Changes to support ELF strip and objcopy on dynamically linked
	files.
	* elfcode.h (elf_fake_sections): Add prototype.
	(bfd_section_from_shdr): Make a BFD section from an SHT_HASH
	section, and from an SHT_DYNSYM section, and from the dynamic
	string table section.
	(elf_object_p): Set D_PAGED if there is a program header.
	(elf_make_sections): Remove.
	(fix_up_strtabs): Remove.
	(elf_fake_sections): Rewrite.  Now sets sh_entsize.
	(assign_section_numbers): Rewrite.  Now sets sh_link and sh_info
	for all sections.
	(elf_compute_section_file_positions):  Don't call obsolete
	functions elf_make_sections or fix_up_strtabs.
	(swap_out_syms): Set sh_addralign to FILE_ALIGN rather than 4.
	(NAME(bfd_elf,write_object_contents)): Permit writing DYNAMIC
	objects.
	(elf_section_from_bfd_section): Treat SHT_DYNSYM like other normal
	sections.  If an SHT_REL or SHT_RELA section is allocated or uses
	an unusual symbol table, permit a BFD section to map to it.
	Permit most SHT_STRTAB sections to have a BFD section mapped to
	them.
	(elf_bfd_final_link): Don't set sh_link, sh_info or sh_entsize
	fields of dynamic sections here; do it in assign_section_numbers.
	* elf32-target.h, elf64-target.h: Add D_PAGED to permitted object
	flags.