Report when multiple values are returned from a function implicitly

[jim-wordelman-msft]

Summary of the new feature

I'd like to be able to run a command such that if I implicitly return values as well as have a return statement that it is flagged.

Ex
function fun1 { mkdir (Join-Path $env:TEMP "myFolder"); return $true }

This should produce an error/warning because mkdir (New-Item) is actually returning a value though we also explicitly return $true.