Always use WaitForSingleObjectEx() as a fallback in SDL_SYS_DelayNS()

That logic isn't specific to the Visual Studio build environment. Also switched it to use CreateEvent(), which works back to Windows XP.

src/timer/windows/SDL_systimer.c

@@ -25,13 +25,13 @@
 #include "../../core/windows/SDL_windows.h"
 
 
-#ifdef CREATE_WAITABLE_TIMER_HIGH_RESOLUTION
-static void SDL_CleanupWaitableTimer(void *timer)
+static void SDL_CleanupWaitableHandle(void *handle)
 {
-    CloseHandle(timer);
+    CloseHandle(handle);
 }
 
-HANDLE SDL_GetWaitableTimer(void)
+#ifdef CREATE_WAITABLE_TIMER_HIGH_RESOLUTION
+static HANDLE SDL_GetWaitableTimer(void)
 {
     static SDL_TLSID TLS_timer_handle;
     HANDLE timer;
@@ -40,13 +40,28 @@ HANDLE SDL_GetWaitableTimer(void)
     if (!timer) {
         timer = CreateWaitableTimerExW(NULL, NULL, CREATE_WAITABLE_TIMER_HIGH_RESOLUTION, TIMER_ALL_ACCESS);
         if (timer) {
-            SDL_SetTLS(&TLS_timer_handle, timer, SDL_CleanupWaitableTimer);
+            SDL_SetTLS(&TLS_timer_handle, timer, SDL_CleanupWaitableHandle);
         }
     }
     return timer;
 }
 #endif // CREATE_WAITABLE_TIMER_HIGH_RESOLUTION
 
+static HANDLE SDL_GetWaitableEvent(void)
+{
+    static SDL_TLSID TLS_event_handle;
+    HANDLE event;
+
+    event = SDL_GetTLS(&TLS_event_handle);
+    if (!event) {
+        event = CreateEvent(NULL, FALSE, FALSE, NULL);
+        if (event) {
+            SDL_SetTLS(&TLS_event_handle, event, SDL_CleanupWaitableHandle);
+        }
+    }
+    return event;
+}
+
 Uint64 SDL_GetPerformanceCounter(void)
 {
     LARGE_INTEGER counter;
@@ -81,22 +96,19 @@ void SDL_SYS_DelayNS(Uint64 ns)
     }
 #endif
 
-    {
-        const Uint64 max_delay = 0xffffffffLL * SDL_NS_PER_MS;
-        if (ns > max_delay) {
-            ns = max_delay;
-        }
+    const Uint64 max_delay = 0xffffffffLL * SDL_NS_PER_MS;
+    if (ns > max_delay) {
+        ns = max_delay;
+    }
+    const DWORD delay = (DWORD)SDL_NS_TO_MS(ns);
 
-#if defined(_MSC_FULL_VER) && (_MSC_FULL_VER <= 180030723)
-        static HANDLE mutex = 0;
-        if (!mutex) {
-            mutex = CreateEventEx(0, 0, 0, EVENT_ALL_ACCESS);
-        }
-        WaitForSingleObjectEx(mutex, (DWORD)SDL_NS_TO_MS(ns), FALSE);
-#else
-        Sleep((DWORD)SDL_NS_TO_MS(ns));
-#endif
+    HANDLE event = SDL_GetWaitableEvent();
+    if (event) {
+        WaitForSingleObjectEx(event, delay, FALSE);
+        return;
     }
+
+    Sleep(delay);
 }
 
 #endif // SDL_TIMER_WINDOWS