PR32663, ld buffer overflow reading .debug_info

When reading debug info to print an error message, we'll be reading
the debug info off disk, not using edited debug info.  sec->rawsize
if non-zero is the correct size.

	PR 32663
	* dwarf2.c (_bfd_dwarf2_slurp_debug_info): Use
	bfd_get_section_limit_octets to properly size debug sections.