simple c10 implementation for std::call_once (#78051)
A long standing bug on std::call_once: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66146
It could hang during re-entry after an exception handling.
Added a c10 implementation yielding a bulky mutex. Not the most efficient thing but at least it shouldn't hang.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/78051
Approved by: https://github.com/albanD
