How to deal with interdependent dlang PRs?

[Dennis]

On Thursday, 25 May 2023 at 15:37:00 UTC, Quirin Schroll wrote:
> Is there a process? I can’t be the first one running into this.

Doing it in 3 PRs is the process. This is one of the reasons why 
druntime was merged into dmd's repository. I remember someone 
saying that if you name the git branches the same, the CI checks 
out the PR's corresponding branch in other repositories, but I 
have no experience doing this so I'm not sure it will work.