[Bug debug/68860] [6 regression] FAIL: gcc.dg/guality/pr36728-1.c -O3 -g line 16 arg1 == 1

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68860

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 37097
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37097&action=edit
gcc6-pr68860-lto.patch

I've noticed that the new tests still fail with LTO.
It seems the reason is that LTO ignores DECL_HAS_DEBUG_ARGS_P etc., so this
stuff is just lost.
I've added some changes so that this is streamed, but it seems that is not
enough, DECL_ORIGIN of the decls is wrong, so it isn't used anyway.
BTW, Honza, why is:
      if (code == VAR_DECL
          && DECL_HAS_DEBUG_EXPR_P (t))
        visit (DECL_DEBUG_EXPR (t));
used in hash_tree?  Depends on what the function is used for, if it is for code
generation or something like that, better it should not depend on the debug
info stuff...