Windows: add Thread implementation

So we can make a worker thread that the guest (hopefully) won't see.

Source/Windows/ARM64EC/Module.cpp

@@ -36,6 +36,7 @@ $end_info$
 #include "Common/Exception.h"
 #include "Common/ImageTracker.h"
 #include "Common/InvalidationTracker.h"
+#include "Common/Threads.h"
 #include "Common/OvercommitTracker.h"
 #include "Common/TSOHandlerConfig.h"
 #include "Common/CPUFeatures.h"
@@ -581,6 +582,7 @@ NTSTATUS ProcessInit() {
   InitSyscalls();
 
   FEX::Windows::InitCRTProcess();
+  FEX::Windows::SetupThreadHandlers();
   const auto ExecutablePath = FEX::Windows::GetExecutableFilePath();
   const auto ExecutableName = FEX::Windows::BaseName(ExecutablePath);
   FEX::Config::LoadConfig(fextl::string {ExecutableName}, _environ, FEX::ReadPortabilityInformation());