[flang][runtime] Catch error on Ew.0 output editing (#78522)

An Ew.0(Ee) or Ew.0(Ee) output edit descriptor with a scale factor of
zero is an error condition, unless the output edit descriptor was
originally Gw.0(Ee), list-directed, or just E0/D0 with no .d part.

Fixes https://github.com/llvm/llvm-project/issues/78390.