fix Issue 11216 - Make synchronized statement `nothrow`

- require Object.Monitor lock and unlock functions to be nothrow

- change methods of all core.sync classes to nothrow

__Requires__ dmd pull https://github.com/D-Programming-Language/dmd/pull/4115
[Issue 11216](https://issues.dlang.org/show_bug.cgi?id=11216 "Make synchronized statement `nothrow`")