warm

Warm the eval path — compile AND run — so the first real eval pays none of it on the tick thread. iterator { yield(1) } is the widest single shape: it compiles a suspend state machine (a superset of a scalar snippet) and is the only one that reaches the snippet loader and the cross-tick path. Running it, not just compiling it, is also what puts those classes in front of recordWorkingSet — what never runs here never enters the preload classlist, and is never preloaded on any later launch either.