Where possible at least, and disable-able with `-nocteval`.
`$lcu` doesn't work because it uses ports `P, G, CI, CO` instead of the standard `A, B, C, Y`.
`$alu` and `$fa` have more than one output so they don't work either (and in the case of `$alu` it has extra inputs too).
`$macc` is at least supported, but `CellTypes::eval()` doesn't have an implementation so it fails (which would also be true for `$lcu`, `$alu`, and `$fa`; if they weren't being rejected based on ports).
Also add `test_cell -list [all|evaluable|missing]` which prints the list of cell types supported by test_cell, cell types marked evaluable, and cell types marked evaluable but not supported by test_cell respectively. Potential for listing cell types supported by test_cell but *not* marked evalulable, though that list is currently empty.
Add `tests/various/evaluable.sh` to exercise this.
