[Bug c++/80014] [6/7 Regression] Caret missing in error message

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80014

--- Comment #2 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
The issue is that we have a range where caret == start, at the given location,
but where finish == UNKNOWN_LOCATION, for some reason, and so this clause fires
in diagnostic-show-locus.c:layout::layout:

797           if (finish.file != m_exploc.file)
798             continue;

Hence layout.m_layout_ranges has no ranges, and hence
layout::should_print_annotation_line_p returns false