[llvm] [flang-rt] Fix TypeCategory for quad-precision COMPLEX (PR #168090)

[via llvm-commits]

jeanPerier wrote:

> I'd like to add a testcase (check the generated LLVM IR for the correct type selection). Where's the best place to put it?

You could add a test like this using a `fir.box<cpmlx.complex<f128>>` type instead of the derived type. The resulting descriptor structure should contain the type code value.

https://github.com/llvm/llvm-project/pull/168090