* dwarf2read.c (dwarf2_section_info): Add comment.
	(dwp_file): Split loaded_cutus into loaded_cus, loaded_tus.
	All uses updated.
	(dwarf2_section_empty_p): Rename arg from "info" to "section".
	(dwarf2_read_section): Delete unused local "header".  Add section
	name to error message.
	(create_dwo_in_dwp): Tweak comment.
	(MAX_NR_DWO_SECTIONS): Combine count of .debug_macro + .debug_macinfo.