ext/reflection: Add test for ReflectionParameter::getDeclaringFunction() with a ReflectionMethod creation from a Closure (#13987)

ext/reflection/tests/closures_bound_getDeclaringFunction.phpt

@@ -0,0 +1,43 @@
+--TEST--
+Closures via getParameters() and getDeclaringFunction() calling reflection_method_factory() with an internal object being set
+--FILE--
+<?php
+
+class A {}
+class B extends A {}
+
+$closure = function($op1, $op2 = 0): self { };
+
+$b = new B();
+$fn = $closure->bindTo($b, B::class);
+
+const CLOSURE_NAME = '{closure:' . __FILE__ . ':6}';
+
+$rClosure = new ReflectionFunction($fn);
+var_dump($rClosure->name == CLOSURE_NAME);
+
+$params = $rClosure->getParameters();
+unset ($rClosure);
+$closureFromParam = $params[0]->getDeclaringFunction();
+var_dump($closureFromParam::class);
+var_dump($closureFromParam->name == CLOSURE_NAME);
+
+$rClass = new ReflectionClass($b);
+$rMethods = $rClass->getMethods();
+var_dump($rMethods);
+
+try {
+    $rMethod = new ReflectionMethod($b, CLOSURE_NAME);
+    var_dump($rMethod);
+} catch (\Throwable $e) {
+    echo $e::class, ': ', $e->getMessage(), PHP_EOL;
+}
+
+?>
+--EXPECTF--
+bool(true)
+string(16) "ReflectionMethod"
+bool(true)
+array(0) {
+}
+ReflectionException: Method B::{closure:%s:6}() does not exist