Another shot at fixing the compiler warnings under Cygwin/MingW.

include/SDL_thread.h

@@ -68,11 +68,6 @@ typedef struct SDL_Thread SDL_Thread;
 #ifdef __OS2__
 typedef int (*pfnSDL_CurrentBeginThread)(void (*func)(void *), void *, unsigned, void *arg); 
 typedef void (*pfnSDL_CurrentEndThread)(void);
-#elif __GNUC__
-typedef unsigned long (__cdecl *pfnSDL_CurrentBeginThread) (void *, unsigned,
-        unsigned (__stdcall *func)(void *), void *arg, 
-        unsigned, unsigned *threadID);
-typedef void (__cdecl *pfnSDL_CurrentEndThread)(unsigned code);
 #else
 typedef uintptr_t (__cdecl *pfnSDL_CurrentBeginThread) (void *, unsigned,
         unsigned (__stdcall *func)(void *), void *arg, 

src/thread/win32/SDL_systhread.c

@@ -36,12 +36,7 @@
 #include <process.h>
 #endif
 
-#if __GNUC__
-typedef uintptr_t (__cdecl *pfnSDL_CurrentBeginThread) (void *, unsigned,
-        unsigned (__stdcall *func)(void *), void *arg, 
-        unsigned, unsigned *threadID);
-typedef void (__cdecl *pfnSDL_CurrentEndThread)(unsigned code);
-#elif defined(__WATCOMC__)
+#if defined(__WATCOMC__)
 /* This is for Watcom targets except OS2 */
 #if __WATCOMC__ < 1240
 #define __watcall
@@ -65,7 +60,7 @@ typedef struct ThreadStartParms
   pfnSDL_CurrentEndThread pfnCurrentEndThread;
 } tThreadStartParms, *pThreadStartParms;
 
-static unsigned __stdcall RunThread(void *data)
+static DWORD WINAPI RunThread(LPVOID data)
 {
   pThreadStartParms pThreadParms = (pThreadStartParms)data;
   pfnSDL_CurrentEndThread pfnCurrentEndThread = NULL;

src/video/wincommon/SDL_sysevents.c

@@ -820,7 +820,8 @@ static int WINAPI ToUnicode9xME(UINT vkey, UINT scancode, const BYTE *keystate,
 {
 	BYTE	chars[2];
 
-	if (ToAsciiEx(vkey, scancode, keystate, (WORD*)chars, 0, GetKeyboardLayout(0)) == 1) {
+	/* arg #3 should be const BYTE *, but cygwin lists it as PBYTE. */
+	if (ToAsciiEx(vkey, scancode, (PBYTE) keystate, (WORD*)chars, 0, GetKeyboardLayout(0)) == 1) {
 		return MultiByteToWideChar(codepage, 0, chars, 1, wchars, wsize);
 	}
 	return 0;