Add phpt tests

tests/compiler/array/array-push-empty-unpack.phpt

@@ -0,0 +1,24 @@
+--TEST--
+array_push retains its required array argument when an unpacked list is empty
+--FILE--
+<?php
+
+function main(): void
+{
+    $values = [];
+    array_push($values, ...[]);
+    var_dump($values);
+
+    array_push($values, ...[1, 2]);
+    var_dump($values);
+}
+?>
+--EXPECT--
+array(0) {
+}
+array(2) {
+  [0]=>
+  int(1)
+  [1]=>
+  int(2)
+}

tests/compiler/closure/static-closure-delayed-callback.phpt

@@ -0,0 +1,45 @@
+--TEST--
+static closure created in an instance method remains a valid delayed callback
+--FILE--
+<?php
+
+final class CallbackHolder
+{
+    private Closure $callback;
+
+    public function __construct(Closure $callback)
+    {
+        $this->callback = $callback;
+    }
+
+    public function invoke(): mixed
+    {
+        return ($this->callback)();
+    }
+}
+
+final class CallbackFactory
+{
+    public function create(): CallbackHolder
+    {
+        return new CallbackHolder(
+            static function (): never {
+                throw new LogicException('expected callback');
+            },
+        );
+    }
+}
+
+function main(): void
+{
+    $callback = (new CallbackFactory())->create();
+
+    try {
+        $callback->invoke();
+    } catch (LogicException $error) {
+        echo $error->getMessage(), "\n";
+    }
+}
+?>
+--EXPECT--
+expected callback