Workaround for compiling with /W4 warnings on Visual C++.

include/SDL_assert.h

@@ -86,8 +86,14 @@ This also solves the problem of...
 disable assertions.
 */
 
+#ifdef _MSC_VER  /* stupid /W4 warnings. */
+#define SDL_NULL_WHILE_LOOP_CONDITION (-1 == __LINE__)
+#else
+#define SDL_NULL_WHILE_LOOP_CONDITION (0)
+#endif
+
 #define SDL_disabled_assert(condition) \
-    do { (void) sizeof ((condition)); } while (0)
+    do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION)
 
 typedef enum
 {
@@ -140,7 +146,7 @@ extern DECLSPEC SDL_assert_state SDLCALL SDL_ReportAssertion(SDL_assert_data *,
             } \
             break; /* not retrying. */ \
         } \
-    } while (0)
+    } while (SDL_NULL_WHILE_LOOP_CONDITION)
 
 #endif  /* enabled assertions support code */