[flang-commits] [flang] [flang][openmp]Add UserReductionDetails and use in DECLARE REDUCTION (PR #131628)

[Mats Petersson via flang-commits]

Leporacanthicus wrote:

> There is a crash in `Fortran::semantics::IsReductionAllowedForType` for the following test.
> 
[snip big chunk of code]

> pure logical function is_reduction_valid()
>   !$omp declare reduction (bar : integer : omp_out = omp_out + omp_in) initializer (omp_priv = 0)
>   is_reduction_valid = .false.
> end function is_reduction_valid
> ```

Fixed all three of the code snippets that fail, and added tests for checking that it works.

https://github.com/llvm/llvm-project/pull/131628