https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83778
--- Comment #2 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Presumably we should simply strip the location from arg, though there are some
places with:
/* Call get_element_number to validate arg1 if it is a constant. */
if (TREE_CODE (arg1) == INTEGER_CST)
(void) get_element_number (TREE_TYPE (arg0), arg1);
which suggests any such stripping needs to happen there.
