In an upcoming patch, D142556, Clang is proposed to be changed to emit
line locations that are inlined at line 0. This clashed with the behavior of
GetDIENamesAndRanges() which used 0 as a default value to determine if
file, line or column numbers had been set. Users of that function then
checked for any non-0 values when setting up the call site:
if (call_file != 0 || call_line != 0 || call_column != 0)
[...]
which did not work with the Clang change since all three values then
could be 0.
This changes the function to use std::optional to catch non-set values
instead.
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D142552
98c3dc3fa7