Fixed warnings in optimize build.
Fixed warnings in optimize build.

libfirm/libfirm,jonashaag/libfirm,MatzeB/libfirm,MatzeB/libfirm,jonashaag/libfirm,libfirm/libfirm,jonashaag/libfirm,libfirm/libfirm,MatzeB/libfirm,libfirm/libfirm,jonashaag/libfirm,MatzeB/libfirm,MatzeB/libfirm,MatzeB/libfirm,jonashaag/libfirm,libfirm/libfirm,MatzeB/libfirm,jonashaag/libfirm,jonashaag/libfirm