This commit introduces a new checker (StopChecker) for STOP
and ERROR STOP Fortran statements along with a test code.
Signed-off-by: Paul Osmialowski <pawel.osmialowski@arm.com>
Original-commit: flang-compiler/f18@c554174562
Reviewed-on: https://github.com/flang-compiler/f18/pull/367
Tree-same-pre-rewrite: false