[llvm] [ConstraintElimination] Use SCEV ranges information for Loop counter (PR #91457)

[via llvm-commits]

v01dXYZ wrote:

I switch the PR to draft as there is a failing test: `polly Support/pipelineposition.ll`

``` console
Input was:
<<<<<<
          22:  n/a
          23:  Statements {
          24:  Stmt_body_i
          25:  Domain :=
          26:  [n] -> { Stmt_body_i[i0, i1] : 0 <= i0 < n and 0 <= i1 < n };
          27:  Schedule :=
next:84'0                 X error: no match found
          28:  [n] -> { Stmt_body_i[i0, i1] -> [i0, i1] };
next:84'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
next:84'1      ?                                            possible intended match
          29:  MustWriteAccess := [Reduction Type: NONE] [Scalar: 0]
next:84'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          30:  [n] -> { Stmt_body_i[i0, i1] -> MemRef_A[i0 + i1] };
next:84'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          31:  }
next:84'0     ~~~
          32:  Function: caller
next:84'0     ~~~~~~~~~~~~~~~~~~
          33:  Region: %entry.split---%polly.merge_new_and_old
next:84'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           .
           .
           .
>>>>>>
```

https://github.com/llvm/llvm-project/pull/91457