PR binutils/15205

	PR binutils/15205
	* dwarf.c (SAFE_BYTE_GET): New macro - checks remaining buffer
	space before calling byte_get.
	(SAFE_BYTE_GET_AND_INC): New macro.
	(SAFE_SIGNED_BYTE_GET): New macro.
	(SAFE_SIGNED_BYTE_GET_AND_INC): New macro.
	(SAFE_BYTE_GET64): New macro.
	(process_extened_line_op): Use new macros.  Use strnlen when
	appropriate.
	(fetch_indirect_string): Likewise.
	(get_FORM_name): Likewise.
	(decode_location_expression): Likewise.
	(read_and_display_attr_value): Likewise.
	(process_debug_info): Likewise.
	(display_debug_lines_raw): Likewise.
	(display_debug_lines_decoded): Likewise.
	(display_debug_pubnames): Likewise.
	(display_debug_macinfo): Likewise.
	(get_line_filename_and_dirname): Likewise.
	(display_debug_macro): Likewise.
	(display_loc_list): Likewise.
	(display_loc_list_dwo): Likewise.
	(display_debug_aranges): Likewise.
	(display_debug_ranges): Likewise.
	(frame_display_row): Likewise.
	(display_debug_frames): Likewise.