Add dwarf2_per_objfile parameter to dwarf2_read_addr_index

Pass it all the way from the symbol batons.  This allows removing a
dwarf2_per_cu_data::dwarf2_per_objfile reference.

gdb/ChangeLog:

	* dwarf2/read.h (dwarf2_read_addr_index): Add dwarf2_per_objfile
	parameter.
	* dwarf2/read.c (dwarf2_read_addr_index): Likewise.
	* dwarf2/loc.c (decode_debug_loclists_addresses): Add
	dwarf2_per_objfile parameter.
	(decode_debug_loc_dwo_addresses): Likewise.
	(dwarf2_find_location_expression): Update.
	(class dwarf_evaluate_loc_desc) <get_addr_index>: Update.
	(locexpr_describe_location_piece): Add dwarf2_per_objfile
	parameter.
	(disassemble_dwarf_expression): Add dwarf2_per_objfile
	parameter.
	(locexpr_describe_location_1): Likewise.
	(locexpr_describe_location): Update.

Change-Id: I8414755e41a87c92f96e408524cc7aaccf086cda