Template instantiation files?

in ippl/src there are a lot of template instantiation files that are unused as far as I can see:

ippl/src/AppTypes/inst/*
ippl/src/DataSource/inst/*
ippl/src/Field/inst/*

etc.

E.g. ippl/src/AppTypes/inst/AntiSymTenzor_1D.cpp:

// include files
#include "AppTypes/AntiSymTenzor.h"

// 1D instantiations
template class AntiSymTenzor<int,1U>;
template class AntiSymTenzor<IPPL_PRECISION_TYPE,1U>;

Are these needed (might be nice for testing?), or can they be deleted?

cc: @gsell @adelmann @kraus