Update Windows GCC toolchain
- GCC binaries We may have to make a decision on this soon. The issue is that upstream has not been able to make a 32 bit GCC release because of a regression in Ada. I had been talking to the Ada people, but they don't seem very interested in solving it as they use the mingw and not mingw-w64 toolchains. So the msys2 people have just not updated the 32 bit toolchains that depend on GCC.
This is an awkward position as it means if we stick to ustream versions we'd have to support two different GCC ABIs at the same time. There's a larger chance that the 32 bit toolchain will bitrot here. With GCC 9 coming the toolchain is nearing two years old, and GCC 9 has improvements I'd like to have.
The problem is, Ada does something funky with the EH since GCC 8, debugging this requires knowlegde of Ada's internals, which really only Ada core has. So one thing we should consider is spinning our own binaries. Upstream is still updating the build recipes, we'd just have to disable ada and run both a 32 bit build and a 64 bit build. We should do this at least for the next release until this mess is sorted out. Maybe it will be for GCC 10 with enough stink raised upstream. I'd be happy to spin them if you want to do this.
In short, it sounds like we will need to build our own GCC packages for Windows in the near term (e.g. GHC 8.10).