auto merge of #12849 : nick29581/rust/doubles, r=alexcrichton

src/libsyntax/parse/parser.rs

@@ -770,6 +770,7 @@ pub fn replace_token(&mut self,
                          next: token::Token,
                          lo: BytePos,
                          hi: BytePos) {
+        self.last_span = mk_sp(self.span.lo, lo);
         self.token = next;
         self.span = mk_sp(lo, hi);
     }