[flang] Merge pull request flang-compiler/f18#615 from flang-compiler/jpr-fix-581

Fix issue 581: extended derived type kind parameter comparison 

Original-commit: flang-compiler/f18@4670ae020b45848380fe0150b48a45b46aab0402
Reviewed-on: https://github.com/flang-compiler/f18/pull/615