[flang] Semantics checker for STOP and ERROR STOP statements - remove one more function from tools

Signed-off-by: Paul Osmialowski <pawel.osmialowski@arm.com>

Original-commit: flang-compiler/f18@9937b524fab7408aac9885ce737716047ec3493e
Reviewed-on: https://github.com/flang-compiler/f18/pull/367
Tree-same-pre-rewrite: false