Fix address violation errors parsing corrupt binary files.

Fix address violation errors parsing corrupt binary files.

	PR 21813
binutils* rddbg.c (read_symbol_stabs_debugging_info): Check for an empty
	string whilst concatenating symbol names.

bfd	* mach-o.c (bfd_mach_o_canonicalize_relocs): Pass the base address
	of the relocs to the canonicalize_one_reloc routine.
	* mach-o.h (struct bfd_mach_o_backend_data): Update the prototype
	for the _bfd_mach_o_canonicalize_one_reloc field.
	* mach-o-arm.c (bfd_mach_o_arm_canonicalize_one_reloc): Add
	res_base parameter.  Use to check for corrupt pair relocs.
	* mach-o-aarch64.c (bfd_mach_o_arm64_canonicalize_one_reloc):
	Likewise.
	* mach-o-i386.c (bfd_mach_o_i386_canonicalize_one_reloc):
	Likewise.
	* mach-o-x86-64.c (bfd_mach_o_x86_64_canonicalize_one_reloc):
	Likewise.

	* vms-alpha.c (_bfd_vms_slurp_eihd): Make sure that there is
	enough data in the record before attempting to parse it.
	(_bfd_vms_slurp_eeom): Likewise.

	(_bfd_vms_slurp_egsd): Check for an invalid section index.
	(image_set_ptr): Likewise.
	(alpha_vms_slurp_relocs): Likewise.