bespillutil: Remove impossible case in gen_assure_different_pattern()
bespillutil: Remove impossible case in gen_assure_different_pattern()

This case cannot happen anymore nowadays, instead we have some code that
turns CopyKeeps into Keeps after the SSA reconstruction there.

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