fix Issue 13446 - Can't use executeShell/escapeShellFileName to redirect to file whose name starts with &

https://issues.dlang.org/show_bug.cgi?id=13446
Agreed. I did a lot of work for `find!(R, E)`, so I could do it, but I'm a bit busy ATM. I could do it by friday. Or if you want to do it, I can review.