Changing extension file from c to cpp in dmd

[deadalnix via Digitalmars-d]

https://github.com/D-Programming-Language/dmd/pull/4382

This has been a recurrent request. Considering how things are 
going, it won't get in. Make your voice heard or do not complain 
about it in the future.

D won't make any progress with this talk but do not act attitude. 
If you want something but aren't even prepared to defend it when 
other are doing the work for you, you are wasting everybody's 
time by posting here.