[flang-commits] [flang] [flang] Put ISO_Fortran_binding.h where it can be easily used (PR #68756)

[Pete Steinfeld via flang-commits]

psteinfeld wrote:

After all of this discussion, I'm convinced that the right place to put this test is in the llvm cross project tests ([//github.com/llvm/llvm-project/tree/main/cross-project-tests](https://github.com/llvm/llvm-project/tree/main/cross-project-tests) as was suggested earlier by @tschuett.

I'll abandon this change.

https://github.com/llvm/llvm-project/pull/68756