Contribute mingw-builds changes upstream

[ogrisel]

Most changes from the mingwpy-dev branch of the mingwpy/mingw-builds repo could be contributed upstream as additional options. Let's try to contribute them as individual pull requests to see if upstream is interested.

[ogrisel]

For reference here is the link to the commits of the mingwpy-dev branch:

https://github.com/mingwpy/mingw-builds/commits/mingwpy-dev

[carlkl]

@ogrisel, I propose to first test the latest checkins and then decide howto spilt this into individual PRs for upstream. The latest checkins have to be partially reworked: i.e. the patch for mingw-w64-crt https://github.com/mingwpy/mingw-builds/blob/aa34b84eab6e5a7c044c26f87940e68e53da92ed/patches/mingw-w64/fpclassify.patch should be written partially not as patch but as perl or sed script. I haven't worked this out yet.

[carlkl]

Probably I will create a repository with simpler and easier to maintain build scripts rather than sitting on the top of https://github.com/niXman/mingw-builds.
The problem with this approach is to stay in sync with all of the necessary patches of the original https://github.com/niXman/mingw-builds. These patches however have to be revised anyway and checked against the gcc patches of https://github.com/Alexpux/MINGW-packages/tree/master/mingw-w64-gcc-git. In the long term such a repository will be easier to maintain compared to patching or hacking mingw-builds.

[techtonik]

Do you plan to make the process system independent?