(ElfW, ELFW): Use it. * elf/Makefile (headers): Add elfclass.h. * sysdeps/wordsize-32/elfclass.h: New file. * sysdeps/wordsize-64/elfclass.h: New file. * sysdeps/alpha/Implies: Add wordsize-64. * sysdeps/i386/Implies: Add wordsize-32. * sysdeps/m68k/Implies: Add wordsize-32. * sysdeps/mips/Implies: Add wordsize-32. * sysdeps/sparc/Implies: Add wordsize-32.