Integer promotion issue

[HuskyNator]

On Sunday, 26 January 2020 at 23:16:40 UTC, Walter Bright wrote:
> On 1/26/2020 5:01 AM, Guillaume Piolat wrote:
>> Pretty sure a LOT of code would break if C++ or D would 
>> abandon this rule
>
> Worst of all, the breakage would be silent.

Could this be added as a compiler flag?
This would probably fix a lot of annoyances, without causing 
issues in older codebases.