mov reg,0 vs xor reg,reg in core.atomic ?

[Kagamin via Digitalmars-d-learn]

https://randomascii.wordpress.com/2012/12/29/the-surprising-subtleties-of-zeroing-a-register/
> But there was at least one out-of-order design that did not 
> recognize xor reg, reg as a special case: the Pentium Pro. The 
> Intel Optimization manuals for the Pentium Pro recommended 
> “mov” to zero a register.