Fix invalid memory access attempting to read the compression header of a too-small...

Fix invalid memory access attempting to read the compression header of a too-small compressed section.

	PR binutils/21149
	* readelf.c (get_compression_header): Add size parameter.  Check
	size against sizeof compression header before attempting to
	extract the header.
	(process_section_headers): Pass size to get_compression_header.
	(dump_section_as_strings): Likewise.
	(dump_section_as_bytes): Likewise.
	(load_specific_debug_section): Likewise.