Fix Phobos dependencies on autodecoding

[Walter Bright]

On 8/15/2019 5:09 AM, Vladimir Panteleev wrote:
> I sent a few PRs for the modules that I am listed as a code owner of.

Can you please add a link to those PRs in
https://github.com/dlang/phobos/pull/7130 ?

I think such references to how Phobos fixed its dependencies on autodecode will 
be valuable to programmers who want to fix theirs.