Cannot use generic functions based on tensor.DataTypes in yaegi code

[rcoreilly]

Due to traefik/yaegi#1700 inability to represent generic type constraints in reflect, we cannot use some pretty important generic functions in tensorfs and table:

• tensorfs.Value (workhorse function; has workaround of specific types defined on Node)
• table.AddColumn, table.InsertColumn -- have workarounds too.

One possibility is to try to import the type constraint into the yaegi code, but it is not clear that this would translate to the Go compiled version, but maybe? Or just give it an any? will experiment.

[rcoreilly]

manually changing the tensor.DataType to any in the generated import code did not work.. seems to be grabbing from the actual guy too, not just using our definition?