Port stdlib/public/stubs/GlobalObjects to Windows

[hughbe]

This avoids an assertion/crash compiling swift code once the stdlib and compiler has been built.

[compnerd]

Can we change this to use C++11's <random> interfaces instead? I feel like that is more standards compliant and doesnt require us to consider seeding issues and can give us the same number space to pull from.

[compnerd]

@jckarter and @jrose-apple, I think you guys should chime in here as well.

[hughbe]

Something like this could work, and we could get rid of all the platform specific code:

  std::random_device rd;
  std::mt19937_64 mt(rd());
  std::uniform_int_distribution<uint64_t> dist;

  while (true)
  {
    std::cout << dist(mt) << "\n";
  }

[jrose-apple]

Seems reasonable to me, but this bit of code is very much in service of the stdlib (to change hashing behavior between runs). @dabrahams?

[jrose-apple]

We'd also be fine with using external libraries on Windows if we had to, as long as they're installed on systems by default. We link to Foundation on Apple platforms!

[compnerd]

Thanks @hughbe, this looks much better!

[compnerd]

@swift-ci please test and merge

[jrose-apple]

Um, I'd definitely still like Dave to take a look. This happens as part of a static constructor.

[compnerd]

@jrose-apple, yeah, I was thinking about that after wards. I think that we should also benchmark this to make sure it doesn't giant the startup too much.

[compnerd]

@swift-ci please test

[swift-ci]

Build failed
Jenkins build - Swift Test OS X Platform
Git Commit - 427aa901ab9fa35d4fbca4c8a26b68753dbf868d
Test requested by - @compnerd

[swift-ci]

Build failed
Jenkins build - Swift Test Linux Platform
Git Commit - 427aa901ab9fa35d4fbca4c8a26b68753dbf868d
Test requested by - @compnerd

[compnerd]

CC: @dabrahams mind taking a look? this is one of the few pieces that prevents building on Windows.

[dabrahams]

I'm going to pass this over to @airspeedswift because I know he's interested in creating a public random number facility around this basic ideas.

[compnerd]

@airspeedswift think you can get to this soon? This is the last piece needed to repair the windows builds!

[hughbe]

@airspeedswift friendly ping!

[dabrahams]

LGTM; merging