Return statements in sync methods need to be "yield break;" instead of "return;"

[JeroMiya]

In sync functions in Dart, you can just return; without yielding a value to break the function. In C# the equivalent is yield break.

https://github.com/JeroMiya/xamarin.flutter/blob/master/FlutterSDK/src/Foundation/Diagnostics.cs#L1097-L1098

{
if (message.Length+startOffset<width){
yield message;
return ;
}

Note: Implementing this implies that the code outputting the return statement can be aware of whether the return statement is within a sync function or a regular function. That is not currently the case - so part of solving this issue is to pass down the method and/or function context (or some stripped down version of same) into the entity processing functions that need it.