dmd foreach loops throw exceptions on invalid UTF sequences, use replacementDchar instead

[Adam D Ruppe]

On Friday, 5 November 2021 at 14:10:35 UTC, deadalnix wrote:
> This shouldn't do anything related to unicode at all.

Well, it doesn't. That was apparently just a typo, as the 
comments in the bug report quickly pointed out, as the thing is 
when you specifically request dchar out of char, NOT when you are 
just working on chars (which is the default).