[Bug tree-optimization/128142] [16/17 Regression] Vector (x + y) >> 1 folded to .AVG_FLOOR although the signed sum can wrap with -fwrapv since r16-1112

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128142

--- Comment #1 from Drea Pinski <pinskia at gcc dot gnu.org> ---
The easy way of fixing this instead of get_nonzero_bits to use ranger to make
sure the add does not overflow.

That is:
gimple_match_range_of_expr (vr0, @0)
gimple_match_range_of_expr (vr1, @1)
range_op_handler (PLUS_EXPR).overflow_free_p (vr0, vr1)