[Bug tree-optimization/96075] [8/9/10 Regression] bogus alignment for negative step grouped access

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96075

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
On the 10 branch we "optimize" the load as

  _19 = MEM[(double *)vectp_y.4_7 + 8B];
  _17 = {0, _19};

possibly because of the gap.