ia32: Simplify handling of nodes in create_proj_for_store(), which have mode M already.
ia32: Simplify handling of nodes in create_proj_for_store(), which have mode M already.

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