Upstreaming Windows patches

[jakirkham]

Currently we are carrying a few patches that are needed for Windows builds. Curious whether these can be upstreamed

https://github.com/conda-forge/graphviz-feedstock/blob/ef22cacde0dfd559ed0d64aed89fc56d50b60c92/recipe/meta.yaml#L10-L13

[nehaljwani]

The third patch is on my TODO list, unless someone beats me to it 😉 I need to revisit the other two patches, sometime in the near future.

[michaelweinold]

Any update on this? It seems that the patches are causing build failures on other platforms also, cf.:

• https://github.com/conda-forge/graphviz-feedstock/pull/135