Fix seg-faults when running readelf on fuzzed binaries.
    
    	PR binutils/20440
    	* dwarf.c (display_debug_lines_decoded): Add checks for running
    	off the end of the section when populating the directory table and
    	file table.
    	(frame_display_row): Set max_regs equal to ncols.
    	(load_specific_debug_section): If the section is compressed, but
    	it is not big enough to hold a compression header then warn and
    	return 0.