Document -lstdc++fs requirement for std::filesystem

	* doc/xml/manual/using.xml (table.cmd_options): Document that the
	C++17 Filesystem implementation also needs -lstdc++fs.

From-SVN: r260011

libstdc++-v3/ChangeLog

 2018-05-07  Jonathan Wakely  <jwakely@redhat.com>
 
+	* doc/xml/manual/using.xml (table.cmd_options): Document that the
+	C++17 Filesystem implementation also needs -lstdc++fs.
+
 	PR libstdc++/85671
 	* include/bits/fs_path.h (operator/): Permit copy elision.
 	* include/experimental/bits/fs_path.h (operator/): Likewise.

libstdc++-v3/doc/xml/manual/using.xml

@@ -99,7 +99,9 @@
       <entry><literal>-lstdc++fs</literal></entry>
       <entry>Linking to <filename class="libraryfile">libstdc++fs</filename>
         is required for use of the Filesystem library extensions in
-        <filename class="headerfile">&lt;experimental/filesystem&gt;</filename>.
+        <filename class="headerfile">&lt;experimental/filesystem&gt;</filename>
+        and the C++17 Filesystem library in
+        <filename class="headerfile">&lt;filesystem&gt;</filename>.
       </entry>
     </row>