testsuite: fix cgrun051 exit code

Signed-off-by: Austin Seipp <austin@well-typed.com>

testsuite/tests/codeGen/should_run/all.T

@@ -48,7 +48,7 @@ test('cgrun047', normal, compile_and_run, [''])
 test('cgrun048', normal, compile_and_run, [''])
 test('cgrun049', normal, compile_and_run, ['-funbox-strict-fields'])
 test('cgrun050', normal, compile_and_run, [''])
-test('cgrun051', normal, compile_and_run, [''])
+test('cgrun051', [exit_code(1)], compile_and_run, [''])
 test('cgrun052', only_ways(['optasm']), compile_and_run, ['-funbox-strict-fields'])
 test('cgrun053', normal, compile_and_run, [''])
 test('cgrun054', normal, compile_and_run, [''])