[luatex] New \pdf... primitives

[Joseph Wright]

Hello all,

Setting up some tests to work with the v0.85 code, I notice that the
suggestion in the manual

  \edef\pdfhorigin{\pdfvariable horigin}

yields with \show\pdfhorigin

  \pdf_horigin=\pdf_horigin

which is accessible using \csname or catcode changes. That seems odd
based on the fact this change has been made at all: is this a passing bug?

Joseph