[Ada] Lock-free implementation of protected objects

[Geert Bosch]

On Jul 23, 2012, at 10:32, Iain Sandoe wrote:

>> Looks good to me, go ahead, although I'm a bit surprised that you got an error,
>> can you clarify what error you got?
> 
> IIRC, that the flag was undefined. 
> If it's important I can revert the fix in my local tree and re-build.
> Iaim

No need to do that. Indeed, the flag must be defined for 
all versions of system.ads. Please apply the patch, it 
really seems to be just an oversight.

I'd consider this could even have been fixed under the "obvious"
rule. Thanks very much, Iain!

  -Geert