Fix memory access violations triggered by running objdump on fuzzed binaries.

Fix memory access violations triggered by running objdump on fuzzed binaries.

	PR binutils/17512
	* elf-m10300.c (mn10300_info_to_howto): Replace assertion with an
	error message.  Never return an invalid howto pointer.
	* elf32-cr16.c (cr16_info_to_howto): Likewise.
	* elf32-crx.c (elf_crx_info_to_howto): Likewise.
	* elf32-i370.c (i370_elf_info_to_howto): Likewise.
	* elf32-mcore.c (mcore_elf_info_to_howto): Likewise.
	* elf32-microblaze.c (microblaze_elf_info_to_howto): Likewise.
	* elf32-mips.c (mips_elf32_rtype_to_howto): Likewise.
	* elf32-pj.c (pj_elf_info_to_howto): Likewise.
	* elf32-ppc.c (ppc_elf_info_to_howto): Likewise.
	* elf32-spu.c (spu_elf_info_to_howto): Likewise.
	* elf32-v850.c (v850_elf_info_to_howto_rela): Likewise.
	* elf32-vax.c (rtype_to_howto): Likewise.
	* elf64-alpha.c (elf64_alpha_info_to_howto): Likewise.
	* elf64-mips.c (mips_elf64_rtype_to_howto): Likewise.
	* elfn32-mips.c (sh_elf_info_to_howto): Likewise.
	* elf32-sh.c (sh_elf_info_to_howto): Likewise.
	(sh_elf_reloc): Check that the reloc is in range.
	* reloc.c (bfd_perform_relocation): Check that the section is big
	enough for the entire reloc.
	(bfd_generic_get_relocated_section_contents): Report unexpected
	return values from perform_reloc.