ir: Fix codegen of ?*T types where T is zero-sized
* Fix codegen for optional types that decay to a pointer, the type
behaves as a boolean
* Fix comptime evaluation of zero-sized arrays, always initialize the
internal array elements
Closes #4673
1f44b29724LemonBoy committed on 3/10/2020, 2:08:56 AM· committed by Andrew Kelleyparent638d5c3