[XeTeX] Simple test stopped producing math symbols

[Neal Becker]

I just updated to latest fedora rawhide version of texlive, and now this 
simple test stopped working.  The text 'pi' is OK, but the mathmode 'pi' 
produces no output.  Anyone see anything wrong here?

% -*- coding: utf-8-unix -*-
% format using xelatex
\documentclass{article}
\usepackage[no-math]{fontspec}
%\usepackage{fontspec}
\usepackage{xunicode,xltxtra}

%\defaultfontfeatures{Mapping=tex-text}
%\setromanfont{Latin Modern Roman} % I don't get the pi
\setromanfont{STIXGeneral} % this works for me
%\setromanfont{Charis SIL} % this works for me
%\setromanfont{Doulos SIL} % this works for me

\begin{document}
What is π?
\begin{equation}
x^2 + 2x = π
\end{equation}

%1/2 \quad 1/4 \\
%\addfontfeature{Fractions=On}
%1/2 \quad 1/4 \\
\end{document}