[ 2021-01-15; Telecon prioritization ]

Set priority to 2 following reflector and telecon discussions.

The specification of [stacktrace.entry.query] uses the terms "presumed or actual name of the source file" and "actual line number". It makes reference to [cpp.predefined], which introduces the term "presumed". It does not clearly define the term, but it describes how the presumed values can be modified with preprocessor directives. However, there is no definition whatsoever of "actual".

The term should either be defined, or we should strike the "actual" parts of the stacktrace wording. We should consult implementers about this.

I don't have a proposed resolution, but if we want to keep "actual", then perhaps we should define both "presumed" and "actual" in [cpp.predefined].