[Bug libstdc++/104866] [12 Regression] this_thread_sleep.h doesn't compile if _GLIBCXX_NO_SLEEP is defined

[dv at vollmann dot ch via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104866

--- Comment #3 from dv at vollmann dot ch ---
Thanks.
Tested for AVR, works :-)