Upgrade to libxml 2.9.2 and libxslt 1.1.28

third_party/libxml/src/xzlib.h

Index: third_party/libxml/src/xzlib.h
diff --git a/third_party/libxml/src/xzlib.h b/third_party/libxml/src/xzlib.h
new file mode 100644
index 0000000000000000000000000000000000000000..29ba55e740bcab381a84fc574ecdb65efd475f7c
--- /dev/null
+++ b/third_party/libxml/src/xzlib.h
@@ -0,0 +1,19 @@
+/**
+ * xzlib.h: header for the front end for the transparent suport of lzma
+ *          compression at the I/O layer
+ *
+ * See Copyright for the status of this software.
+ *
+ * Anders F Bjorklund <afb@users.sourceforge.net>
+ */
+
+#ifndef LIBXML2_XZLIB_H
+#define LIBXML2_XZLIB_H
+typedef void *xzFile;           /* opaque lzma file descriptor */
+
+xzFile __libxml2_xzopen(const char *path, const char *mode);
+xzFile __libxml2_xzdopen(int fd, const char *mode);
+int __libxml2_xzread(xzFile file, void *buf, unsigned len);
+int __libxml2_xzclose(xzFile file);
+int __libxml2_xzcompressed(xzFile f);
+#endif /* LIBXML2_XZLIB_H */