Update the xrange object description to reflect the removal of deprecated

features.

Doc/lib/libstdtypes.tex

@@ -401,9 +401,9 @@ new buffer object.
 Xrange objects are similar to buffers in that there is no specific
 syntax to create them, but they are created using the
 \function{xrange()} function.\bifuncindex{xrange}  They don't support
-slicing or concatenation, but do support repetition, and using
-\code{in}, \code{not in}, \function{min()} or \function{max()} on them
-is inefficient.
+slicing, concatenation, or repetition, and using \keyword{in},
+\keyword{not} \keyword{in}, \function{min()} or \function{max()} on
+them is inefficient.
 \obindex{xrange}
 
 Most sequence types support the following operations.  The \samp{in} and