Move doc comment desugaring into the parser.

src/libsyntax/tokenstream.rs

@@ -214,11 +214,9 @@ impl TokenTree {
                  mtch: &[TokenTree],
                  tts: &[TokenTree])
                  -> macro_parser::NamedParseResult {
+        let diag = &cx.parse_sess().span_diagnostic;
         // `None` is because we're not interpolating
-        let arg_rdr = lexer::new_tt_reader_with_doc_flag(&cx.parse_sess().span_diagnostic,
-                                                         None,
-                                                         tts.iter().cloned().collect(),
-                                                         true);
+        let arg_rdr = lexer::new_tt_reader(diag, None, tts.iter().cloned().collect());
         macro_parser::parse(cx.parse_sess(), arg_rdr, mtch)
     }