Generated frontend.h files produces different results on windows and on linux

[12345swordy]

This is bad, I had to rely on someone else with a Linux machine to generate the frontend header file for me in order to pass certain test suits.

[Geod24]

This is best reported as an issue (and already is): https://issues.dlang.org/show_bug.cgi?id=21423

[12345swordy]

That doesn't change the current fact that it is already making contributing to dmd more difficult than necessarily.

[ljmf00]

Shouldn't this issue be blocker importance?

[MoonlightSentinel]

Note that one can also git apply the diff generated by the CI (automation would be nice though - maybe possible via Github Actions?)