[dmd-internals] process / tool issues

[Brad Roberts via dmd-internals]

So, what's missing from the current tooling and processes that has 
allowed these two scenarios:

1) 3 pull requests to master marked for auto-merge for weeks to not be 
merged:

     https://github.com/dlang/druntime/pull/1679 - 23 days
         broken on continuous-integration/jenkins/pr-merge

     https://github.com/dlang/druntime/pull/1732 - 30 days
         broken on continuous-integration/jenkins/pr-merge

     https://github.com/dlang/druntime/pull/1831 - 9 days
         waiting on continuous-integration/jenkins/pr-merge

2) 7 pull requests to stable to sit for days/weeks/months?  Pulls to 
stable should definitionally be simple low risk changes.  The oldest one 
is from August 2016.

I'm starting this thread in hopes that improvements can be made. 
Minimal time should be spent on how we got to that state or if it's 
anyone's fault.