OSSubprocess for 64bits

Hi guys,

Thanks for Guillermo Polito we now have 64 bits support for OSSubprocess. You can see the required changes in this PR [1]. I made a branch called `support64bits` so that you can help us test it even if CI said it was good [2]. If you do test it and come back to us with the results, please tell us which OS you used.
To install from the branch:
Metacello new
  configuration: ‘OSSubprocess’;
  repository: ‘github://marianopeck/OSSubprocess:support64bits/repository’;
version: #stable;
load.
Roadmap: Current release is v0.2.5. So I will let that release for Pharo <= 5.0. I will make a new release with the Pharo 64 bits and call it v0.3. That release should be used for Pharo 6.x. Once v0.3 is out, I will make a new release v0.4 with some changes I wanted to do since a loooong time and its a small refactor to minimize OSSubprocess dependency on OSProcesses primitives (at VM side). This is thanks to Holger Freyther and Alistair Grant [3]. As that requires a new VM, then v0.4 should be used in Pharo >= 7.0.
Cheers,