Add support for the number and scalar types

[kocsismate]

number is an alias of int|float, scalar is an alias of bool|int|string|float.

[carusogabriel]

@kocsismate If you want to relate this one with https://bugs.php.net/bug.php?id=67837.

[kocsismate]

It's not easy to determine whether scalar/number or their union type counterparts should be displayed

[nikic]

For what it's worth, I'm probably -1 on this one. I think the stubs work showed that these types are actually quite rare. A general type aliasing feature might make sense, but aliasing these two in particular might not be worthwhile anymore.

[kocsismate]

@nikic Interestingly, I see the other way around. :) I don't like general type aliasing, but I think these 2 specific aliases would make sense. Maybe their usage wouldn't be very widespread, but still, they could offer a more expressive alternative to their union type counterparts.

Nevertheless, I'll first try to get to know if there is really interest in this proposal. :)

[moliata]

While I do think that both number and scalar are actually fairly useful type aliases and are used in the PHP documentation itself 1, I do agree with @nikic that general type aliasing might make more sense. When that is in place, we could just make a few default type aliases such as these one.

[kocsismate]

I'm closing this one as I'm not going to pursue an RFC. Mainly because of lack of interest, but also, I'm not sure if reserving the number name is a good idea.