[Bug debug/101905] [9/10/11/12 Regression] Missed debug information for global register variable

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101905

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think adding the location early is most sensible in this case.  As you saw
that might need tickling down adjustments or maybe a special-case of
DECL_REGISTER globals, bypassing most of the
add_location_or_const_value_attribute magic.