https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80161
--- Comment #5 from Jeff Hammond <jeff.science at gmail dot com> --- Thanks for the comments. Indeed, I made all the changes to the containing project to compile in C++ and the problem went away. I will likely just switch to the preprocessor solution for now. For posterity, I found that Clang has the same issue, whereas ICC (Intel) does not. Feel free to close this as WONTFIX/INVALID unless you think it should remain open to motivate the OpenMP IPA changes in GCC 8+.
