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

[Walter Bright]

On 11/7/2021 8:46 AM, Imperatorn wrote:
> https://docs.microsoft.com/en-us/dotnet/standard/base-types/character-encoding

The money quote:

"By default, each object uses replacement fallback to handle strings that it 
cannot encode and bytes that it cannot decode, but you can specify that an 
exception should be thrown instead. For more information, see Replacement 
fallback and Exception fallback."