Add static fat libraries for libjxl for Darwin

It'll use something pkg-config turns up first, but it looks like
brew doesn't have it yet.

3rdp/darwin.release/libjxl/include/jxl/version.h

+/* Copyright (c) the JPEG XL Project Authors. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file.
+ */
+
+/** @addtogroup libjxl_common
+ * @{
+ * @file version.h
+ * @brief libjxl version information
+ */
+
+#ifndef JXL_VERSION_H_
+#define JXL_VERSION_H_
+
+#define JPEGXL_MAJOR_VERSION 0 ///< JPEG XL Major version
+#define JPEGXL_MINOR_VERSION 11 ///< JPEG XL Minor version
+#define JPEGXL_PATCH_VERSION 1 ///< JPEG XL Patch version
+
+/** Can be used to conditionally compile code for a specific JXL version
+ * @param[maj] major version
+ * @param[min] minor version
+ *
+ * @code
+ * #if JPEGXL_NUMERIC_VERSION < JPEGXL_COMPUTE_NUMERIC_VERSION(0,8,0)
+ * // use old/deprecated api
+ * #else
+ * // use current api
+ * #endif
+ * @endcode
+ */
+#define JPEGXL_COMPUTE_NUMERIC_VERSION(major,minor,patch) (((major)<<24) | ((minor)<<16) | ((patch)<<8) | 0)
+
+/* Numeric representation of the version */
+#define JPEGXL_NUMERIC_VERSION JPEGXL_COMPUTE_NUMERIC_VERSION(JPEGXL_MAJOR_VERSION, JPEGXL_MINOR_VERSION, JPEGXL_PATCH_VERSION)
+
+#endif /* JXL_VERSION_H_ */
+
+/** @}*/