Re: [RFA/dwarf] Eliminate dwarf2_tmp_obstack

[Jim Blandy <jimb@redhat.com>]

Daniel Jacobowitz <drow@false.org> writes:
> dwarf2_tmp_obstack serves as a general purpose dumping ground.  After my
> previous patches, there are only two things left on it: the linked list we
> use to fudge GCC 2.95 line number tables (some day soon I think this hack
> should go away; it was primarily for the benefit of the testsuite, and was
> fixed at least as of GCC 3.1), and the block structures created in
> read_attribute_value.
> 
> Both of these are clearly associated with a particular compilation unit.
> If we put them on the comp_unit_obstack, then we don't have any need for
> the global obstack any more.
> 
> Since my following patches change the lifetimes of individual CUs, I felt
> this was a worthwhile cleanup.  OK?

You need to fix up the comments above free_stack_comp_unit; it's no
longer "only used during partial symbol processing".

I'd like free_stack_comp_unit renamed to free_comp_unit_obstack, so
that when I search for comp_unit_obstack, I'll also run into the calls
to make_cleanup that will free it.

Otherwise, looks good.