[flang] Merge pull request flang-compiler/f18#968 from...

[flang] Merge pull request flang-compiler/f18#968 from flang-compiler/jpr-fix-clang-template-step-limit

Fix template step limit issue with clang

Original-commit: flang-compiler/f18@d4cd378290feb05ace2d549fb74db3e48b962f10
Reviewed-on: https://github.com/flang-compiler/f18/pull/968