Fix #2529: explicit protection package #3651

[Kagamin via Digitalmars-d-announce]

On Friday, 22 August 2014 at 15:06:14 UTC, Dmitry Olshansky wrote:
> Example structure:
> mod/package.d
> mod/internal/bar.d
> mod/...
>
> I actually face it in Phobos right now, my blocked pull:
> https://github.com/D-Programming-Language/phobos/pull/2412

I think, it should have structure

std.regex.package;
std.regex.backtracking;
std.regex.ir;

What is the reason to have regex stuff in a remote directory? 
That would make things hard to find and navigate.