bootstrap:passzero: in all Copy_ctor,Operator_eq,Operator_ne enforce identity check
bootstrap:passzero: in all Copy_ctor,Operator_eq,Operator_ne enforce identity check

At the very beginning of the body:

Copy_ctor: if self === other, return.
Operator_eq: if self === other, return true.
Operator_ne: if self === other, return false.

The compiler inserts the test to enforce this semantic constraint. And
avoid this common error when written by hand.

nanocritical/n,nanocritical/n,nanocritical/n,nanocritical/n