9000f73ba3
The ATOMIC_*_LOCK_FREE can evalutate either 0, 1, or 2 which indicate the
lock-free property of the corresponding atomic types (both signed and unsigned).
Value Explanation
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0 The atomic type is never lock-free
1 The atomic type is sometimes lock-free
2 The atomic type is always lock-free
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(cherry picked from commit a5e7901eb9)