2010-09-24 Thomas Schwinge <[email protected]>

2010-09-24  Thomas Schwinge  <[email protected]>

	* elf32-arm.c, elf32-cris.c, elf32-hppa.c, elf32-i370.c, elf32-m32r.c,
	elf32-m68k.c, elf32-microblaze.c, elf32-ppc.c, elf32-score.c,
	elf32-score7.c, elf32-sh.c, elf32-vax.c, elf32-xtensa.c, elf64-alpha.c,
	elf64-hppa.c, elf64-mips.c, elf64-ppc.c, elf64-sparc.c, elfcode.h,
	elflink.c, elfxx-ia64.c, elfxx-mips.c: Use STN_UNDEF when referring to
	the zero symbol index.