I have an updated TeX Live distribution.
Following Fonts for PolyTonic Greek I copied the code exactly:
\documentclass{article}
\usepackage{fontspec}
\defaultfontfeatures{Ligatures=TeX}
\newcommand\test[1]{%
#1\{\fontspec{#1}Βίβλος γενέσεως Ἰησοῦ Χριστοῦ υἱοῦ Δαυὶδ υἱοῦ Ἀβραάμ.}
\par\medskip}
\setlength{\parindent}{0pt}
\begin{document}
\test{CMU Serif}
\test{EB Garamond}
\test{GFS Artemisia}
\test{GFS Baskerville}
\test{GFS Bodoni}
\test{GFS Complutum}
\test{GFS Didot}
\test{GFS Olga}
\test{GFS Porson}
\test{GFS Solomos}
\test{Junicode}
\test{Linux Libertine O}
\test{Old Standard}
\end{document}
into c.tex and then did xelatex c. This returned the following error:
/usr/local/texlive/2013/texmf-dist/tex/latex/tipa/t3cmr.fd)kpathsea:make_tex: Invalid fontname `CMU Serif', contains ' '
fontspec error: "font-not-found" l.14 \test{CMU Serif}
Thus its first objection is to a space in a font name. How can that linked example work with a whole list of fonts with spaces in their names? And it also appears that no font whose name contains the strings "Serif" and "CMU" is part of TeX Live 2013:
find /usr/local/texlive -type f | egrep -i serif | egrep -i cmu
What am I missing?

tlmgr. Alternatively, you can update things manually. If your needs are simple, this is not too onerous. (I used to do this.) – jon Jan 25 '15 at 23:20findis no good in any case. It is not searching by filename - of course the names of the files do not have spaces in them! - but by the postscript name. You can see what the name of a given opentype font is, for example, usingotfinfo -i <path-to-font>but to use it,fontconfigmust also know about it. – cfr Oct 18 '15 at 00:38