How would the parser know to give a "missing continuation" error message? '+$d+$e' is perfectly legal perl code, albeit code which gives rise to the warning "Useless use of addition (+) in void context".
The reason I gave that code as an example is that it's a perfectly normal way of spreading complex expressions over multiple lines: e.g. where you need to add several variables together and the variables have non-trivial (i.e. long) names, e.g.
In this case, the automatic semicolons are unhelpful and will give rise to confusing error messages. So you've just switched one problem for another, and raised the cognitive load - people now need to know about your pragma and also know when its in scope.