|ptr||Pointer to data to XOR atomically.|
|mask||Value to XOR with existing value.|
OSXorAtomic performs an atomic XOR with a value in memory.
This is useful if the value needs to be atomically manipulated by multiple processors.
It does not act as a memory barrier.
2013-05-08 Automated cleanup pass.
2012-07-30 Cleanup Pass
2012-05-04 Match actual prototype.
2010-08-30 Initial version.