Add a pick for 8.19.2 with the Ltac2 debugger (preview)

[jfehrle]

This works now.

I didn't include the patch file PR19247-ported-Fix-coqide-compilation-with-lablgtk-3.1.5-on-windows.patch because I previously included that commit in my branch.

[MSoegtropIMC]

The opam file for coqide misses the dependency. The original one has it here:

https://github.com/ocaml/opam-repository/blob/abac1deff0ec6249cf93f6b25ffdc49ae1caf04c/packages/coqide/coqide.8.19.2/opam#L24

You should copy the original one and deviate from it only as much as required.

[jfehrle]

OK, this works for me, I think it's good. If you merge soon, will this pick be included when you release CP 8.19?
If so, perhaps the announcement of CP 8.19 could briefly mention the Ltac2 debugger and say that more information on it will be sent out shortly (by me)?

Thanks.