void switch expression

[natilivni]

The switch expression syntax introduced in c# 8 is fantastic for writing readable and compact switch statements which are not unnecessarily verbose.

However, one limitation of this syntax is the assumption that the statement must return a value.

I propose that we allow the switch expression to call void methods as follows:

i switch {
  1 => method1(), 
  2 => method2(), 
  _ => method3()
};

[ufcpp]

#2181

[333fred]

Duplicate of #2632.