[flang] [llvm] [mlir] [flang][MLIR][OpenMP] make reduction by-ref toggled per variable (PR #92244)

[Kiran Chandramohan via llvm-commits]

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@@ -272,34 +272,33 @@ def ParallelOp : OpenMP_Op<"parallel", [
     that specify the memory allocator to be used to obtain storage for private values.
 
     Reductions can be performed in a parallel construct by specifying reduction
-    accumulator variables in `reduction_vars` and symbols referring to reduction
-    declarations in the `reductions` attribute. Each reduction is identified
-    by the accumulator it uses and accumulators must not be repeated in the same
-    reduction. The `omp.reduction` operation accepts the accumulator and a
-    partial value which is considered to be produced by the thread for the
-    given reduction. If multiple values are produced for the same accumulator,
-    i.e. there are multiple `omp.reduction`s, the last value is taken. The
-    reduction declaration specifies how to combine the values from each thread
-    into the final value, which is available in the accumulator after all the
-    threads complete.
+    accumulator variables in `reduction_vars`, symbols referring to reduction
+    declarations in the `reductions` attribute, and whether the reduction
+    variable should be passed into the redution region by value or by reference
----------------
kiranchandramohan wrote:

```suggestion
    variable should be passed into the reduction region by value or by reference
```

https://github.com/llvm/llvm-project/pull/92244