cpuinfo: Added SDL_GetSystemPageSize.

Fixes #14201.

include/SDL3/SDL_cpuinfo.h

@@ -344,6 +344,27 @@ extern SDL_DECLSPEC int SDLCALL SDL_GetSystemRAM(void);
  */
 extern SDL_DECLSPEC size_t SDLCALL SDL_GetSIMDAlignment(void);
 
+/**
+ * Report the size of a page of memory.
+ *
+ * Different platforms might have different memory page sizes. In current
+ * times, 4 kilobytes is not unusual, but newer systems are moving to larger
+ * page sizes, and esoteric platforms might have any unexpected size.
+ *
+ * Note that this function can return 0, which means SDL can't determine
+ * the page size on this platform. It will _not_ set an error string to be
+ * retrieved with SDL_GetError() in this case! In this case, defaulting to
+ * 4096 is often a reasonable option.
+ *
+ * \returns the size of a single page of memory, in bytes, or 0 if SDL can't
+ *          determine this information.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.4.0.
+ */
+extern SDL_DECLSPEC int SDLCALL SDL_GetSystemPageSize(void);
+
 /* Ends C function definitions when using C++ */
 #ifdef __cplusplus
 }