Make RangePolicy and TeamPolicy assignable

[dalg24]

Fix #3192

NOTE Not sure what happened with clang-format in the unit test

[crtrott]

what I don't get is how this slipped through … That doesn't make ANY sense whatesoever. Nobody ever tried to assign a policy or make it a member of a class or something like that????

I mean this is ridiculous that this doesn't compile.

    Kokkos::RangePolicy<> pr1, pr2;
    pr1 = pr2;
    pr1 = Kokkos::RangePolicy<>(0,N);
    pr2 = pr1;
    Kokkos::TeamPolicy<> pt1, pt2;
    pt1 = pt2;
    pt1 = Kokkos::TeamPolicy<>(0,N);
    pt2 = pt1;

Also TeamPolicy doesn't have a default constructor???? OMG.

[dalg24]

So should we make them semiregular?

[dalg24]

FYI, in the current HEAD of the develop branch and in all releases of the 3.X series, TeamPolicy is both copy and move assignable.

[dalg24]

We decided we would make them semiregular.

[dalg24]

This is ready.
Use https://github.com/kokkos/kokkos/pull/3196/files/86b9ea346f98df44833f75d18464abe3a30d9bf6
to filter out the clang-format changes