splatVector

pub fn splatVector(
    self: *WipFunction,
    ty: Type,
    elem: Value,
    name: []const u8,
) Allocator.Error!Value {
    const scalar_ty = try ty.changeLength(1, self.builder);
    const mask_ty = try ty.changeScalar(.i32, self.builder);
    const poison = try self.builder.poisonValue(scalar_ty);
    const mask = try self.builder.splatValue(mask_ty, .@"0");
    const scalar = try self.insertElement(poison, elem, .@"0", name);
    return self.shuffleVector(scalar, poison, mask, name);
}