scalarType

pub fn scalarType(self: Type, builder: *const Builder) Type {
    if (self.isFloatingPoint()) return self;
    const item = builder.type_items.items[@intFromEnum(self)];
    return switch (item.tag) {
        .integer,
        .pointer,
        => self,
        .vector,
        .scalable_vector,
        => builder.typeExtraData(Type.Vector, item.data).child,
        else => unreachable,
    };
}