Don't use vma to identify eh_frame personality function

This is all we should need to be able to run the eh_frame parts of
bfd_elf_discard_info before bfd_elf_size_dynamic_sections

	* elf-eh-frame.c (struct cie.personality): Replace val with sym.
	(find_merged_cie): Identify personality functions by (bfd_id,index)
	pair when a local sym is used.