Reduction with & should not widen the type

[eschnett]

This surprised me:

julia> typeof(reduce(&, Int8(0), (Int8(4),)))
Int32

It makes sense of + to widen the type to prevent overflow, but & cannot overflow. I tried to counteract the automatic widening by providing an explicit neutral element, but that didn't help.

I also notice that a + reduction widens Bool to Int64, while a & reduction does not widen it.

Should there be a widereduce in addition to reduce?

Should there be an optional argument T that lets people specify the return type?

[stevengj]

See also #20607

[KristofferC]

julia> typeof(reduce(&, (Int8(4); init=Int8(0))))
Int8