[Bug 49796] Separate IDL-related tools into a separate project

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=49796

--- Comment #2 from KOLANICH  ---
I have created a repo where I have tried to reconstruct the history and then
merged the patches of MinGW-w64 and ReactOS into a single `merged` branch. The
result is here: https://github.com/KOLANICH/widl. I have also done the same
with libwpp (https://github.com/KOLANICH/libwpp). Have not tested yet though.
The next step is to land the latest patches there, and then make it
standalone-buildable using CMake (and thanks to ReactOS project, that has
rewritten most of the build scripts to CMake).