Add EM_386/EM_IAMCU support to elfedit.c

binutils/

	* elfedit.c (enum elfclass): New.
	(input_elf_class): Change type to enum elfclass.
	(output_elf_class): New.
	(elf_class): Change return type to enum elfclass.  Support EM_386
	and EM_IAMCU.
	(update_elf_header): Check if input and output ELF classes match.
	(elf_machine): Support EM_386 and EM_IAMCU.
	(main): Update input_elf_class.  Set output_elf_class.
	* doc/binutils.texi: Update elfedit.

binutils/testsuite/

	* binutils-all/elfedit-5.d: New file.
	* binutils-all/elfedit.exp: Run elfedit-5.