Fix: major revision to valid and invalid numeric literal separator "sibling" characters

[rwaldron]

Q	A
Bug fix?	yes
Breaking change?	yes
New feature?	no
Deprecations?	no
Spec compliancy?	yes
Tests added/pass?	yes
License	MIT

As a result of testing the Babel transform against NLS tests pending for test262, I discovered a pretty serious oversight in my original parsing. This addresses that issue and adds a substantial amount of tests.

[nicolo-ribaudo]

Can we use allowedNumericSeparatorSlibings instead of forbiddenNumericSeparatorSlibings when checking if the caracter before the separator is valid?

[nicolo-ribaudo]

Nit: I would like to avoid repeating all the numbers... What do you think about doing something like this?

const allowedNumericSeparatorSiblings = {};
allowedNumericSeparatorSiblings.bin = [ 48, 49 ];
allowedNumericSeparatorSiblings.oct = [
  ...allowedNumericSeparatorSiblings.bin, 50, 51, 52, 53, 54, 55,
];
allowedNumericSeparatorSiblings.dec = [
  ...allowedNumericSeparatorSiblings.oct, 56, 57,
];

It wouldn't have a too big performance impact, since they would be computed only when babylon is loaded.
Anyway, It's up to you.

[rwaldron]

Sure, I can do that.

[rwaldron]

Looks like I have to update to use indexOf!

[nicolo-ribaudo]

@rwaldron Can you fix the linting errors? npm/yarn run lint -- --fix

[hzoo]

Looks nice the way it is, but prettier wants the newlines..

[hzoo]

Thanks @rwaldron!!

[rwaldron]

Sorry I missed these follow-up messages, I've been afk since Thursday evening.