Std.parseInt() does not parse negative hex numbers on neko/cpp target

[zagortenej]

https://api.haxe.org/Std.html#parseInt says:
"x may also start with a - to denote a negative value."

I'm not sure if this refers to decimal format only or it applies to hex too, so I'm not sure if this is a bug or just the documentation being a bit vague.

The reason why I have doubts is because this code:

trace(Std.parseInt("-0xa0"));

produces these results on following targets:

eval: -160
hashlink: -160
js: -160
java: -160
python: -160
neko: 0
cpp 0

I'm running unit tests on eval target, and from time to time on neko, and thought (based on the API docs) -0xa0 is a valid value, but it looks like neko and cpp disagree. Maybe it's the case with some of the other targets (flash, c#, php, etc.) these are the only ones I tried.

[zagortenej]

Also:

Std.parseInt("+123");

results in:

eval: 123
hashlink: null
js: 123
java: 123
python: 123
neko: 123
cpp 123

but I think this might not be considered a bug because the documentation does not mention + character as a valid one.

[Simn]

Could you open a pull request that adds the failing cases (also from #10544) as a unit test? That way I can fix it directly on that branch. I'll probably also deal with the problems from #10480 while I'm there.