`symmatu()` and `symmatl()`
This MR implements the symmatu()
and symmatl()
functions via four kernels: symmatl
, symmatu
, symmatl_inplace
, and symmatu_inplace
. Armadillo doesn't implement any higher-level optimizations that make use (specifically) of the symmatl
or symmatu
operations, and so we don't do that here either.