[flang] Merge pull request flang-compiler/f18#552 from flang-compiler/jpr-fix-518

Fix issues flang-compiler/f18#517, flang-compiler/f18#518, and flang-compiler/f18#546

Original-commit: flang-compiler/f18@bc3c549d48a4166c63fbfb312adf0fc7079adeb1
Reviewed-on: https://github.com/flang-compiler/f18/pull/552