libc++ is a new implementation of the C++ standard library, targeting C++11.
Used in the Mapbox GL plugin of Qt Location.
The sources can be found in tmp/qtlocation-everywhere-src-5.15.0/src/3rdparty/mapbox-gl-native.
Project Homepage
Copyright (c) 2009-2014 libc++ developers
MIT and UIUC (BSD-like).