Call thisTid to initialize first thread's message box, bypassing checks against setting thread-local variables from a shared static constructor.
Merge pull request #1376 from yebblies/issue4923

initialize first thread's message box in a normal static ctor, to work around requirement that thread-local variables cannot be set from a shared static constructor.
Fix Issue 10510 - enforce should take any callable function without regard for calling conventions.
Merge pull request #1382 from AndrejMitrovic/Fix10510

Issue 10510 - enforce should take any callable function