Return void from linker callbacks

Return void from linker callbacks

The ldmain.c implementation of these linker callback functions always
return true, so any code handling a false return is dead.  What's
more, some of the bfd backends abort if ever a false return is seen,
and there seems to be some confusion in gdb's compile-object-load.c.
The return value was never meant to be "oh yes, a multiple_definition
error occurred", but rather "out of memory or other catastrophic
failure".

This patch removes the status return on the callbacks that always
return true.  I kept the return status for "notice" because that one
does happen to need to return "out of memory".

include/
	* bfdlink.h (struct bfd_link_callbacks): Update comments.
	Return void from multiple_definition, multiple_common,
	add_to_set, constructor, warning, undefined_symbol,
	reloc_overflow, reloc_dangerous and unattached_reloc.
bfd/
	* aoutx.h: Adjust linker callback calls throughout file,
	removing dead code.
	* bout.c: Likewise.
	* coff-alpha.c: Likewise.
	* coff-arm.c: Likewise.
	* coff-h8300.c: Likewise.
	* coff-h8500.c: Likewise.
	* coff-i960.c: Likewise.
	* coff-mcore.c: Likewise.
	* coff-mips.c: Likewise.
	* coff-ppc.c: Likewise.
	* coff-rs6000.c: Likewise.
	* coff-sh.c: Likewise.
	* coff-tic80.c: Likewise.
	* coff-w65.c: Likewise.
	* coff-z80.c: Likewise.
	* coff-z8k.c: Likewise.
	* coff64-rs6000.c: Likewise.
	* cofflink.c: Likewise.
	* ecoff.c: Likewise.
	* elf-bfd.h: Likewise.
	* elf-m10200.c: Likewise.
	* elf-m10300.c: Likewise.
	* elf32-arc.c: Likewise.
	* elf32-arm.c: Likewise.
	* elf32-avr.c: Likewise.
	* elf32-bfin.c: Likewise.
	* elf32-cr16.c: Likewise.
	* elf32-cr16c.c: Likewise.
	* elf32-cris.c: Likewise.
	* elf32-crx.c: Likewise.
	* elf32-d10v.c: Likewise.
	* elf32-epiphany.c: Likewise.
	* elf32-fr30.c: Likewise.
	* elf32-frv.c: Likewise.
	* elf32-ft32.c: Likewise.
	* elf32-h8300.c: Likewise.
	* elf32-hppa.c: Likewise.
	* elf32-i370.c: Likewise.
	* elf32-i386.c: Likewise.
	* elf32-i860.c: Likewise.
	* elf32-ip2k.c: Likewise.
	* elf32-iq2000.c: Likewise.
	* elf32-lm32.c: Likewise.
	* elf32-m32c.c: Likewise.
	* elf32-m32r.c: Likewise.
	* elf32-m68hc1x.c: Likewise.
	* elf32-m68k.c: Likewise.
	* elf32-mep.c: Likewise.
	* elf32-metag.c: Likewise.
	* elf32-microblaze.c: Likewise.
	* elf32-moxie.c: Likewise.
	* elf32-msp430.c: Likewise.
	* elf32-mt.c: Likewise.
	* elf32-nds32.c: Likewise.
	* elf32-nios2.c: Likewise.
	* elf32-or1k.c: Likewise.
	* elf32-ppc.c: Likewise.
	* elf32-s390.c: Likewise.
	* elf32-score.c: Likewise.
	* elf32-score7.c: Likewise.
	* elf32-sh.c: Likewise.
	* elf32-sh64.c: Likewise.
	* elf32-spu.c: Likewise.
	* elf32-tic6x.c: Likewise.
	* elf32-tilepro.c: Likewise.
	* elf32-v850.c: Likewise.
	* elf32-vax.c: Likewise.
	* elf32-visium.c: Likewise.
	* elf32-xstormy16.c: Likewise.
	* elf32-xtensa.c: Likewise.
	* elf64-alpha.c: Likewise.
	* elf64-hppa.c: Likewise.
	* elf64-ia64-vms.c: Likewise.
	* elf64-mmix.c: Likewise.
	* elf64-ppc.c: Likewise.
	* elf64-s390.c: Likewise.
	* elf64-sh64.c: Likewise.
	* elf64-x86-64.c: Likewise.
	* elflink.c: Likewise.
	* elfnn-aarch64.c: Likewise.
	* elfnn-ia64.c: Likewise.
	* elfxx-mips.c: Likewise.
	* elfxx-sparc.c: Likewise.
	* elfxx-tilegx.c: Likewise.
	* linker.c: Likewise.
	* pdp11.c: Likewise.
	* pe-mips.c: Likewise.
	* reloc.c: Likewise.
	* reloc16.c: Likewise.
	* simple.c: Likewise.
	* vms-alpha.c: Likewise.
	* xcofflink.c: Likewise.
	* elf32-rl78.c (get_symbol_value, get_romstart, get_ramstart): Delete
	status param.  Adjust calls to these and linker callbacks throughout.
	* elf32-rx.c: (get_symbol_value, get_gp, get_romstart,
	get_ramstart): Delete status param.  Adjust calls to these and
	linker callbacks throughout.
ld/
	* ldmain.c (multiple_definition, multiple_common, add_to_set,
	constructor_callback, warning_callback, undefined_symbol,
	reloc_overflow, reloc_dangerous, unattached_reloc): Return void.
	* emultempl/elf32.em: Adjust callback calls.
gdb/
	* compile/compile-object-load.c (link_callbacks_multiple_definition,
	link_callbacks_warning, link_callbacks_undefined_symbol,
	link_callbacks_undefined_symbol, link_callbacks_reloc_overflow,
	link_callbacks_reloc_dangerous,
	link_callbacks_unattached_reloc): Return void.