why:
this allows for passing back information which can eventually be
used for reducing use of exceptions
caveat:
call/create currently needs to un-capture the call-by-reference
(wrapper) argument using the Computation reference inside
why:
the previous approach was replacing the function-lets in
opcode_impl.nim by the particulate table handlers. the test
functions will verify the the handler functions are sort of
correct but not the assignments in the fork tables.
the handler names of old and new for tables are checked here.
caveat:
verifying tables currently takes a while at compile time.