Add zstd.

3rdparty/zstd-1.5.0/zlibWrapper/gzclose.c

@@ -0,0 +1,28 @@
+/* gzclose.c contains minimal changes required to be compiled with zlibWrapper:
+ * - gz_statep was converted to union to work with -Wstrict-aliasing=1      */
+
+/* gzclose.c -- zlib gzclose() function
+ * Copyright (C) 2004, 2010 Mark Adler
+ * For conditions of distribution and use, see http://www.zlib.net/zlib_license.html
+ */
+
+#include "gzguts.h"
+
+/* gzclose() is in a separate file so that it is linked in only if it is used.
+   That way the other gzclose functions can be used instead to avoid linking in
+   unneeded compression or decompression routines. */
+int ZEXPORT gzclose(file)
+    gzFile file;
+{
+#ifndef NO_GZCOMPRESS
+    gz_statep state;
+
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state.file = file;
+
+    return state.state->mode == GZ_READ ? gzclose_r(file) : gzclose_w(file);
+#else
+    return gzclose_r(file);
+#endif
+}