Add test case.

Author: H. S. Teoh

test/runnable/test18076.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+
+dir=${RESULTS_DIR}${SEP}runnable
+output_file=${dir}/test18076.sh.out
+
+echo 'import std.stdio; void main() { writeln("Success"); }' | \
+	$DMD -m${MODEL} -run - > ${output_file} || exit 1
+grep -q '^Success$' ${output_file} || exit 1