Exit with quick_exit when using debug UCRT

[MichalStrehovsky]

Resolves #108640.

Cc @dotnet/ilc-contrib @janvorli

[jkotas]

I expect that this will break tracing tests. Tracing depends on C runtime shutdown notification to close the session:

runtime/src/coreclr/nativeaot/Runtime/startup.cpp

Line 375 in be013ed

atexit(&OnProcessExit);

Also, the same fundamental problem exists in regular coreclr as well.

[janvorli]

It seems that the only way to fix the problem and keep the cleanup at exit untouched would be to link to ucrt dynamically. The cleanup then occurs in DllMain of the library on DLL_PROCESS_DETACH.

[janvorli]

I meant the low level CRT cleanup, not the atexit stuff.