Call to byte_swap_vector should use dst, not d1, because this is
modified by the call to the strided memcpy and will end up pointing
after the end of the destination buffer in that case.
BUG: fix uninitialized-use on invalid sort kind

orign is unset at that point but used in the fail goto,
can probably only be triggered by using the C-api wrong.
Merge pull request #3456 from juliantaylor/uninitialized-use

BUG: fix uninitialized-use on invalid sort kind
Merge pull request #3455 from Hoops/copy_and_swap_stride_dst

Possible memory overwrite in copy_and_swap
BUG: Campanion Matrix was scalar, not matrix for degree 1.

The companion matrices returned by the various polynomial types was
a scalar in the degree one case instead of a 2-D array. Fix that and
add a test to check for that result.

Closes #3459.
Merge pull request #3460 from charris/fix-polynomial-companion-matrices

BUG: Campanion Matrix was scalar, not matrix for degree 1.