As well as all other kinds of expressions
While it's not necessary in a sense that 'for' loop can not be plain expression,
i.e. it can't be an argument for safe-call etc., but laziness is still very convenient property.
E.g. within attached test they were generated twice in case of last expression
of coroutine block, because coroutine related codegen part is built upon
assumption that all expressions should be generated lazy.
Denis Zharkov
b6ccd03ef4