[Bug libstdc++/98034] New: std::atomic_signed_lock_free and std::atomic_unsigned_lock_free not defined

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98034

            Bug ID: 98034
           Summary: std::atomic_signed_lock_free and
                    std::atomic_unsigned_lock_free not defined
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: redi at gcc dot gnu.org
                CC: rodgertq at gcc dot gnu.org
  Target Milestone: ---

C++20 adds these typedefs.

For linux they should be atomic<int> and atomic<unsigned>, because they can use
futex for waiting and notifying. I don't know about other targets.