vulkan: Use the same dispatch magic value as LunarG

 * implementation-defined data). On return from the creation function, the

 * implementation-defined data). On return from the creation function, the

 * 'magic' field must contain HWVULKAN_DISPATCH_MAGIC; the loader will overwrite

 * 'magic' field must contain HWVULKAN_DISPATCH_MAGIC; the loader will overwrite

 * the 'vtbl' field.

 * the 'vtbl' field.

 *

 * NOTE: The magic value and the layout of hwvulkan_dispatch_t match the LunarG

 * loader used on platforms, to avoid pointless annoying differences for

 * multi-platform drivers. Don't change them without a good reason. If there is

 * an opportunity to change it, using a magic value that doesn't leave the

 * upper 32-bits zero on 64-bit platforms would be nice.

 */

 */

#if defined(__LP64__)

#define HWVULKAN_DISPATCH_MAGIC 0x01CDC0DE

#define HWVULKAN_DISPATCH_MAGIC UINT64_C(0xCA11AB1E00C0DE00)

#elif defined(__ILP32__)

#define HWVULKAN_DISPATCH_MAGIC UINT32_C(0xCA11AB1E)

#else

#error "unknown pointer size?!"

#endif

typedef union {

typedef union {

    uintptr_t magic;

    uintptr_t magic;

    const void* vtbl;

    const void* vtbl;