Enable rudimentary support for valgrind, including functions that tell valgrind to do a leak check at runtime. See xemacs-patches message with ID <870180fe1001060942k2b06ef1bn2631c5f226b5e6b2@mail.gmail.com>.

#!/bin/sh
if
test -r $2
then
if
cmp $1 $2 > /dev/null
then
echo $2 is unchanged
rm -f $1
else
mv -f $1 $2
fi
else
mv -f $1 $2
fi