[flang-commits] [flang] [llvm] [mlir] [flang][OpenMP] Support the FULL clause on the UNROLL construct (PR #214115)

[Spencer Bryngelson via flang-commits]

sbryngelson wrote:

@Meinersbur @tblah @kparzysz could one of you take a look? Picked you from the precedents: you
wrote #144785 and clang's `#pragma omp unroll`, and you both approved the `partial` support in
#206642 that this mirrors.

Two things worth a second opinion beyond the lowering itself:

- Moving `full`/`partial` from `allowedOnceClauses` to `allowedExclusiveClauses` on `OMP_Unroll`.
  That is an `OMP.td` edit, but only flang reads that field, and `clang/test/OpenMP` is clean.
- The constant-trip-count requirement for `full`. I put it in semantics to match clang's
  `err_omp_unroll_full_variable_trip_count`; tell me if you would rather it live elsewhere or be a
  separate patch.

CI is green.


https://github.com/llvm/llvm-project/pull/214115