Fix Phobos dependencies on autodecoding

[Walter Bright]

On 8/16/2019 10:52 AM, H. S. Teoh wrote:
> So in other words, we should encode 1, I, |, and l with exactly the same
> value, because in print, they aII look about the same anyway, and the
> user is well able to figure out from context which one is meant. After
> a11, once you print the string the semantic distinction is gone anyway,
> and human beings are very good at te||ing what was actually intended in
> spite of the ambiguity.
> 
> Bye-bye unambiguous D lexer, we hardly knew you; now we need to rewrite
> you with a context-sensitive algorithm that figures out whether we meant
> 11, ||, II, or ll in our source code encoded in Walter Encoding.

Fonts people use for programming take pains to distinguish them.