[flang-commits] [flang] [flang] still apply vectorization cost model with IVDEP (PR #180760)

[Tom Eccles via flang-commits]

https://github.com/tblah commented:

In my testing classic flang does set `!{!"llvm.loop.vectorize.enable", i1 true}` for
```
subroutine ivdep_test4
  integer :: a(10)
  !dir$ ivdep
  do i=1,10
     a(i)=i
  end do
end subroutine ivdep_test4
```

I would prefer that we stick to the behaviour in classic flang.

I tested using ACfL 24.04. I don't think there are any downstream changes which would change this.

https://github.com/llvm/llvm-project/pull/180760