disable closure iterator changes in #23787 unless `-d:nimOptIters` is enabled (#24108)

refs #24094, soft reverts #23787

#23787 turned out to cause issues as described in #24094, but the
changes are still positive, so it is now only enabled if compiling with
`-d:nimOptIters`. Unfortunately the changes are really interwoven with
each other so the checks for this switch in the code are a bit messy,
but searching for `nimOptIters` should give the necessary clues to
remove the switch properly later on.

Locally tested that nimlangserver works but others can also check.

0 files changed, 0 insertions, 0 deletions