refactor: simplify bare array question lowering test to assert key optimization properties

Remove assertions on dataset construction opcodes (OpDataSet, OpPush) that
bake in the materialization implementation detail. Instead, assert only the
key optimization property: no counting-loop OpIncr and presence of OpLength
for the emptiness check.

test/integration/compiler/compiler_array_question_lowering_test.go

@@ -20,18 +20,14 @@ func TestArrayQuestionLowering(t *testing.T) {
 }
 
 func expectBareArrayQuestionLowering(prog *bytecode.Program) error {
-	expected := map[bytecode.Opcode]int{
-		bytecode.OpDataSet: 1,
-		bytecode.OpPush:    1,
-		bytecode.OpLength:  1,
-		bytecode.OpGt:      1,
-		bytecode.OpIncr:    0,
+	// The optimization must eliminate the counting loop (no OpIncr)
+	// and use a length/emptiness check instead.
+	if got := inspect.CountOpcode(prog, bytecode.OpIncr); got != 0 {
+		return fmt.Errorf("expected no OpIncr (counting loop eliminated), got %d", got)
 	}
 
-	for opcode, count := range expected {
-		if got := inspect.CountOpcode(prog, opcode); got != count {
-			return fmt.Errorf("expected %d %s ops, got %d", count, opcode, got)
-		}
+	if !inspect.HasOpcode(prog, bytecode.OpLength) {
+		return fmt.Errorf("expected OpLength for emptiness check")
 	}
 
 	return nil