Add support for ELF shared libraries.

	Add support for ELF shared libraries.
	* ld.h (ld_config_type): Add field dynamic_link.
	* ldmain.c (main): Initialize config.dynamic_link to false.  Warn
	on attempts to use -r with -relax, -call_shared or -s.
	* lexsup.c (longopts): Separate OPTION_CALL_SHARED from
	OPTION_NON_SHARED.  Add OPTION_IGNORE.  Adjust macro values
	accordingly.  Add "dy" and "non_shared" options.  Change "Qy" to
	OPTION_IGNORE for now.  Handle OPTION_CALL_SHARED and
	OPTION_NON_SHARED by setting dynamic_link field accordingly.
	Handle OPTION_IGNORE by ignoring it.  Clear dynamic_link field for
	-r and -Ur.
	* ldfile.c (ldfile_open_file): If config.dynamic_link is true, try
	opening a file with a .so extension first.
	* emultempl/elf32.em: New file.
	* emulparams/elf32_sparc.sh (TEXT_START_ADDR): Change to 0x10000.
	(NONPAGED_TEXT_START_ADDR): Likewise.
	(TEMPLATE_NAME): Define as elf32.
	(DATA_PLT): Define.
	* emulparams/elf_i386.sh (TEMPLATE_NAME): Define as elf32.
	* scripttempl/elf.sc: Add placement for new dynamic sections.
	Don't use CREATE_OBJECT_SYMBOLS.  Define _etext, _edata and _end
	outside of any section.  Don't use ALIGN(8); just let one section
	VMA follow another.  Put .dynbss in .bss.  Don't mention debugging
	sections; they'll be handled correctly anyhow.
	* Makefile.in (eelf_i386.c): Depend upon elf32.em, not generic.em.