[Bug tree-optimization/68335] [6 Regression][GRAPHITE] ICE: tree check: expected ssa_name, have real_cst in add_phi_arg_for_new_expr, at sese.c:1373

[spop at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68335

--- Comment #4 from Sebastian Pop <spop at gcc dot gnu.org> ---
testcase added in r230630