Add support for Cooperative Suspend when running on Mono

Informs mono runtime that Job System, Thread Pool or Content Load threads can wait when they are going idle between tasks.

Source/Engine/Threading/ThreadPool.cpp

@@ -15,6 +15,7 @@
 #include "Engine/Platform/CPUInfo.h"
 #include "Engine/Platform/Thread.h"
 #include "Engine/Profiler/ProfilerMemory.h"
+#include "Engine/Scripting/Internal/InternalCalls.h"
 
 FLAXENGINE_API bool IsInMainThread()
 {
@@ -117,6 +118,7 @@ int32 ThreadPool::ThreadProc()
     Platform::SetThreadAffinityMask(THREAD_POOL_AFFINITY_MASK((int32)index));
 #endif
     ThreadPoolTask* task;
+    MONO_THREAD_INFO_TYPE* monoThreadInfo = nullptr;
 
     // Work until end
     while (Platform::AtomicRead(&ThreadPoolImpl::ExitFlag) == 0)
@@ -125,12 +127,15 @@ int32 ThreadPool::ThreadProc()
         if (ThreadPoolImpl::Jobs.try_dequeue(task))
         {
             task->Execute();
+            MONO_THREAD_INFO_GET(monoThreadInfo);
         }
         else
         {
+            MONO_ENTER_GC_SAFE_WITH_INFO(monoThreadInfo);
             ThreadPoolImpl::JobsMutex.Lock();
             ThreadPoolImpl::JobsSignal.Wait(ThreadPoolImpl::JobsMutex);
             ThreadPoolImpl::JobsMutex.Unlock();
+            MONO_EXIT_GC_SAFE_WITH_INFO;
         }
     }