[XeTeX] unicode-math (I think) redefines \slash

[Joel C. Salomon]

Using all packages as of TL ’10 pretest.

At one point in my document I needed an optional line-break after a
slash, but
	blah blah overfull line UNIX\slash Linux
didn’t break.  Inserting the line
	\show\slash
showed me that \slash was now simply the character ‘/’.  Even
re-defining it in my preamble didn’t work right away; I needed
	\AtBeginDocument{\def\slash{/\penalty \exhyphenpenalty}}
since unicode-math also does its manipulations then.

Is there a way to avoid this conflict?  I.e., have uicode-math set
\slash to whatever it needs, but only in math mode, and have \slash in
text mode keep the “\penalty \exhyphenpenalty” bits?

—Joel Salomon