The way to Unity, pt.2

[polybiusproxy]

A big roadblock for Unity on Windows is the use of exceptions, and to implement those, we need to do some preparations.
The idea is to use APCs—for this, we must switch our code to use alertable waits with Win32 wrappers on:

• Pthread condition waits
• Pthread mutexes
• Orbis and POSIX semaphores
• Thread sleeps
• Event flags (was not seen on Unity, thus not a priority)

This will allow us to properly implement exceptions later on.

[polybiusproxy]

This PR noticably regresses performance in UE4 titles. This is especially noticable in Dragon Ball Z Kakarot. A severe performance regression is also noticable in updated versions of Hatsune Miku Project Diva X.

And Touhou Luna Nights takes my CPU again

This might be due to the fact that we're using WaitForSingleObjectEx now (just as we did previously with winpthreads), which uses quite the whole thread on infinite waits. This was removed with the pthread rewrite where we moved to STL semaphores which use atomics and WaitOnAddress and WakeByAddressAll/WakeByAddressSingle on Windows.

Unfortunately, I don't see a way of resolving this as, to my knowledge, there is no other documented method of having alertable waits.

[StevenMiller123]

My reported performance regressions are solved after the latest pushes. Both Diva X v1.02 and Dragon Ball Z Kakarot are performing as they do on current main builds now.

[GHU7924]

I found a couple of Unity games for the test, but they failed at startup.

Build e1ecfb8

CUSA05297 INSIDE

[Debug] exception.cpp:sceKernelInstallExceptionHandler:77: Unreachable code!
Missing exception implementation

CUSA23081 Untitled Goose Game

[Debug] exception.cpp:sceKernelInstallExceptionHandler:77: Unreachable code!
Missing exception implementation