gdb/dwarf: remove pretend_language parameter from load_full_{comp,type}_unit

I noticed that load_full_comp_unit and load_full_type_unit didn't use
their pretend_language parameter.  Remove them, and then remove more
things that were needed to get the language value to that point,
including the dwarf2_queue_item field.

Change-Id: Ie8cb21c54ae49da065a1b0a20bf18ccb93961d1a
Approved-By: Tom Tromey <tom@tromey.com>
2 files changed