gnu: Add texlive-xprintlen.

* gnu/packages/tex.scm (texlive-xprintlen): New variable.

gnu: Add texlive-xpeek.

* gnu/packages/tex.scm (texlive-xpeek): New variable.

gnu: Add texlive-xpunctuate.

* gnu/packages/tex.scm (texlive-xpunctuate): New variable.

gnu: Add texlive-xoptarg.

* gnu/packages/tex.scm (texlive-xoptarg): New variable.

gnu: Add texlive-xnewcommand.

* gnu/packages/tex.scm (texlive-xnewcommand): New variable.

gnu: Add texlive-xltabular.

* gnu/packages/tex.scm (texlive-xltabular): New variable.

gnu: Add texlive-xkcdcolors.

* gnu/packages/tex.scm (texlive-xkcdcolors): New variable.

gnu: Add texlive-xint.

* gnu/packages/tex.scm (texlive-xint): New variable.

gnu: Add texlive-xhfill.

* gnu/packages/tex.scm (texlive-xhfill): New variable.

gnu: Add texlive-xfakebold.

* gnu/packages/tex.scm (texlive-xfakebold): New variable.

gnu: Add texlive-xellipsis.

* gnu/packages/tex.scm (texlive-xellipsis): New variable.

gnu: Add texlive-xdoc.

* gnu/packages/tex.scm (texlive-xdoc): New variable.

gnu: Add texlive-xcpdftips.

* gnu/packages/tex.scm (texlive-xcpdftips): New variable.

gnu: Add texlive-xcookybooky.

* gnu/packages/tex.scm (texlive-xcookybooky): New variable.

gnu: Add texlive-xcolor-solarized.

* gnu/packages/tex.scm (texlive-xcolor-solarized): New variable.

gnu: Add texlive-xcolor-material.

* gnu/packages/tex.scm (texlive-xcolor-material): New variable.

gnu: Add texlive-xcntperchap.

* gnu/packages/tex.scm (texlive-xcntperchap): New variable.

gnu: Add texlive-xbmks.

* gnu/packages/tex.scm (texlive-xbmks): New variable.

gnu: Add texlive-xassoccnt.

* gnu/packages/tex.scm (texlive-xassoccnt): New variable.

gnu: Add texlive-xargs.

* gnu/packages/tex.scm (texlive-xargs): New variable.