BugFix: scalar replacement should not remove volatile Loads/Stores
BugFix: scalar replacement should not remove volatile Loads/Stores

[r18184]

jonashaag/libfirm,8l/libfirm,MatzeB/libfirm,jonashaag/libfirm,libfirm/libfirm,libfirm/libfirm,jonashaag/libfirm,killbug2004/libfirm,killbug2004/libfirm,8l/libfirm,davidgiven/libfirm,jonashaag/libfirm,davidgiven/libfirm,davidgiven/libfirm,MatzeB/libfirm,8l/libfirm,jonashaag/libfirm,davidgiven/libfirm,MatzeB/libfirm,killbug2004/libfirm,killbug2004/libfirm,killbug2004/libfirm,8l/libfirm,MatzeB/libfirm,davidgiven/libfirm,MatzeB/libfirm,libfirm/libfirm,MatzeB/libfirm,8l/libfirm,davidgiven/libfirm,jonashaag/libfirm,davidgiven/libfirm,killbug2004/libfirm,libfirm/libfirm,8l/libfirm,8l/libfirm,MatzeB/libfirm,jonashaag/libfirm,killbug2004/libfirm,libfirm/libfirm