void CoverageMappingWriter::write(raw_ostream &OS) {
// Sort the regions in an ascending order by the file id and the starting
// location.
- std::sort(MappingRegions.begin(), MappingRegions.end());
+ std::stable_sort(MappingRegions.begin(), MappingRegions.end());
// Write out the fileid -> filename mapping.
encodeULEB128(VirtualFileMapping.size(), OS);