[Bug debug/39436] g++ does not emit DW_TAG_try_block or DW_TAG_catch_block

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=39436

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
So for space, on LP64 (and LLP64) hosts, there is a free 32bits in the BLOCK
structure:
```
  tree chain;

  unsigned block_num;

  location_t locus; // unsigned
  location_t end_locus; // unsigned

  tree vars;
```

So I can at least add a 3bit field without increasing the size too.