Build bug on 64-Bit platforms.

Removed improper casts.
Thanks to Joerg Bruehe for the fix.

include/my_global.h

@@ -641,29 +641,17 @@ extern double		my_atof(const char*);
 #endif
 #endif /* defined (HAVE_LONG_LONG) && !defined(ULONGLONG_MAX)*/
 
-#if SIZEOF_LONG == 4
-#define INT_MIN32       ((long) 0x80000000L)
-#define INT_MAX32       ((long) 0x7FFFFFFFL)
-#define UINT_MAX32      ((long) 0xFFFFFFFFL)
-#define INT_MIN24       ((long) 0xFF800000L)
-#define INT_MAX24       0x007FFFFFL
-#define UINT_MAX24      0x00FFFFFFL
-#define INT_MIN16       ((short int) 0x8000)
+#define INT_MIN32       (~0x7FFFFFFFL)
+#define INT_MAX32       0x7FFFFFFFL
+#define UINT_MAX32      0xFFFFFFFFL
+#define INT_MIN24       (~0x007FFFFF)
+#define INT_MAX24       0x007FFFFF
+#define UINT_MAX24      0x00FFFFFF
+#define INT_MIN16       (~0x7FFF)
 #define INT_MAX16       0x7FFF
 #define UINT_MAX16      0xFFFF
-#define INT_MIN8        ((char) 0x80)
-#define INT_MAX8        ((char) 0x7F)
-#else  /* Probably Alpha */
-#define INT_MIN32	((long) (int) 0x80000000)
-#define INT_MAX32	((long) (int) 0x7FFFFFFF)
-#define UINT_MAX32	((long) (int) 0xFFFFFFFF)
-#define INT_MIN24	((long) (int) 0xFF800000)
-#define INT_MAX24	((long) (int) 0x007FFFFF)
-#define UINT_MAX24	((long) (int) 0x00FFFFFF)
-#define INT_MIN16	((short int) 0xFFFF8000)
-#define INT_MAX16	((short int) 0x00007FFF)
-#define UINT_MAX16      ((short int) 0x0000FFFF)
-#endif
+#define INT_MIN8        (~0x7F)
+#define INT_MAX8        0x7F
 
 /* From limits.h instead */
 #ifndef DBL_MIN