Macro spirq::define_ops

macro_rules! define_ops {
    (read_enum: $type:ty: $operands:expr) => { ... };
    ($read_fn:ident: $type:ty: $operands:expr) => { ... };
    ($($opcode:ident { $($field:ident: $type:ty = $read_fn:tt(),)+ })+) => { ... };
}