References to keywords/macros/specvars not rendered correctly in html and pdf

We have a macro keyref that is supposed to provide a cross-ref and have the displayed text printed out with a leading colon and with al the text in a fixed-width font for code. This works for the html doc but not the pdf doc.

The problem is an incorrect definition of the keyref macro:

@macro keyref {arg}
@xref{\arg\, @kwd{\arg\}}
@end macro

The second arg is used for online docs (html). If there's a third arg, it's used for the printed doc (pdf). This needs to be updated to get the printed manual to use the keyword format. See https://www.gnu.org/software/texinfo/manual/texinfo/texinfo.html#Three-Arguments

This also applies to the macref and specvarref macros.