Use `1u` literal for flags/masks calculation

Changes `1 <<` and `1<<` to use `1u`.

include/SDL3/SDL_audio.h

@@ -107,10 +107,10 @@ typedef Uint16 SDL_AudioFormat;
 
 
 /* masks for different parts of SDL_AudioFormat. */
-#define SDL_AUDIO_MASK_BITSIZE       (0xFF)
-#define SDL_AUDIO_MASK_FLOAT         (1<<8)
-#define SDL_AUDIO_MASK_BIG_ENDIAN    (1<<12)
-#define SDL_AUDIO_MASK_SIGNED        (1<<15)
+#define SDL_AUDIO_MASK_BITSIZE       (0xFFu)
+#define SDL_AUDIO_MASK_FLOAT         (1u<<8)
+#define SDL_AUDIO_MASK_BIG_ENDIAN    (1u<<12)
+#define SDL_AUDIO_MASK_SIGNED        (1u<<15)
 
 
 /**

include/SDL3/SDL_filesystem.h

@@ -333,7 +333,7 @@ extern DECLSPEC int SDLCALL SDL_RenamePath(const char *oldpath, const char *newp
 extern DECLSPEC int SDLCALL SDL_GetPathInfo(const char *path, SDL_PathInfo *info);
 
 
-#define SDL_GLOB_CASEINSENSITIVE (1 << 0)
+#define SDL_GLOB_CASEINSENSITIVE (1u << 0)
 
 /**
  * Enumerate a directory tree, filtered by pattern, and return a list.

include/SDL3/SDL_joystick.h

@@ -429,9 +429,9 @@ typedef struct SDL_VirtualJoystickDesc
     Uint16 product_id;  /**< the USB product ID of this joystick */
     Uint16 padding;     /**< unused */
     Uint32 button_mask; /**< A mask of which buttons are valid for this controller
-                             e.g. (1 << SDL_GAMEPAD_BUTTON_SOUTH) */
+                             e.g. (1u << SDL_GAMEPAD_BUTTON_SOUTH) */
     Uint32 axis_mask;   /**< A mask of which axes are valid for this controller
-                             e.g. (1 << SDL_GAMEPAD_AXIS_LEFTX) */
+                             e.g. (1u << SDL_GAMEPAD_AXIS_LEFTX) */
     const char *name;   /**< the name of the joystick */
 
     void *userdata;     /**< User data pointer passed to callbacks */

include/SDL3/SDL_mouse.h

@@ -521,7 +521,7 @@ extern DECLSPEC SDL_bool SDLCALL SDL_CursorVisible(void);
  *
  * \since This macro is available since SDL 3.0.0.
  */
-#define SDL_BUTTON(X)       (1 << ((X)-1))
+#define SDL_BUTTON(X)       (1u << ((X)-1))
 
 #define SDL_BUTTON_LEFT     1
 #define SDL_BUTTON_MIDDLE   2