[Bug tree-optimization/118616] [15 regression] -Waggressive-loop-optimizations warnings in tree-vect-generic.cc on x86

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118616

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
the auto_vec for converts could use N as being 2 too since
supportable_indirect_convert_operation only currently pushes up to 2 elements
and allocating memory in the heap would be slowing than the internal storage
case.

But that is just a small optimization and all.