Use a Pulse-specific _zero_for_deref instead of Low* KrmlLib#592

tahina-pro wants to merge 3 commits intoFStarLang:fstar2FStarLang/pulse:fstar2from

tahina-pro:_taramana_zero_for_dereftahina-pro/pulse:_taramana_zero_for_derefCopy head branch name to clipboard