More work on cleaning out compiler warnings.

src/thread/windows/SDL_systhread.c

@@ -77,7 +77,7 @@ typedef struct ThreadStartParms
     pfnSDL_CurrentEndThread pfnCurrentEndThread;
 } tThreadStartParms, *pThreadStartParms;
 
-static DWORD __stdcall
+static unsigned __stdcall
 RunThread(void *data)
 {
     pThreadStartParms pThreadParms = (pThreadStartParms) data;
@@ -115,7 +115,7 @@ SDL_SYS_CreateThread(SDL_Thread * thread, void *args)
     pfnSDL_CurrentEndThread pfnEndThread = _endthreadex;
 #endif
 #endif /* SDL_PASSED_BEGINTHREAD_ENDTHREAD */
-    unsigned threadid;
+    DWORD threadid = 0;
     pThreadStartParms pThreadParms =
         (pThreadStartParms) SDL_malloc(sizeof(tThreadStartParms));
     if (!pThreadParms) {

src/video/windows/SDL_windowsevents.c

@@ -557,7 +557,8 @@ WIN_WindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
 				for (i = 0; i < num_inputs; ++i) {
 					PTOUCHINPUT input = &inputs[i];
 
-					SDL_TouchID touchId = (SDL_TouchID)input->hSource;
+					const SDL_TouchID touchId = (SDL_TouchID)
+												((size_t)input->hSource);
 					if (!SDL_GetTouch(touchId)) {
 						SDL_Touch touch;