Upgrade to version 3.4 Change-Id: I8d852ea8b76e31dafa2b0efe8f15bc90c09d6961
Eigen is a C++ template library for linear algebra: matrices, vectors, numerical solvers, and related algorithms.
For more information go to http://eigen.tuxfamily.org/.
For pull request, bug reports, and feature requests, go to https://gitlab.com/libeigen/eigen.