[Dlang-internal] The Phantom Zone

[Walter Bright]

The issue that there are too many aged PRs on github that sit around for years 
comes up again and again. I've resisted just closing them, because closing them 
is tantamount to termination with prejudice:

https://en.wikipedia.org/wiki/Termination_of_employment#Rehire_following_termination

and the PR is never seen again. This is squandering our resources. A PR may 
remain open, but is not pulled, for several reasons:

1. it needs work, but the author has left the field
2. it's a good idea whose time has not yet come
3. it's a good idea, but a not good enough implementation, but the PR still 
contains valuable insight, details, and test cases that would be useful for a 
more acceptable implementation
4. it's large and complex and nobody has been willing to expend the effort to do 
a proper review.

But github has a feature we can use for this. We tag these PRs with "Phantom 
Zone" and then close them.

http://superman.wikia.com/wiki/The_Phantom_Zone
(People with terminal diseases would get put in the Phantom Zone until a cure 
could be found.)

They can then be viewed via this link:

https://github.com/dlang/dmd/pulls?q=is%3Apr+is%3Aclosed+label%3A%15Phantom+Zone%15

PRs banished to the Phantom Zone would have to have an explanatory comment 
saying why.

Andrei has suggested calling it "Limbo".