PR32599, objcopy -I ihex: invalid operation

Restores ihex get_symtab_upper_bound to what it was prior to commit
394a3f4f8d.  This will enable objcopy of other no-sym formats too.

	PR 32599
	* libbfd-in.h (_bfd_nosymbols_get_symtab_upper_bound): Define
	as _bfd_long_bfd_0.
	* libbfd.h: Regenerate.