Add reflection hint on Publisher for bean destroy support

Prior to this commit, `DisposableBeanAdapter` supported reactive bean
destroy methods by detected if `Publisher` is available on the
classpath. The AOT engine did not contribute a reflection hint for this
call.

This commit ensures that this reflection hint is registered in all
cases, even if there are no destroy methods detected on beans.

Fixes gh-31278

spring-beans/src/main/java/org/springframework/beans/factory/aot/BeanDefinitionPropertiesCodeGenerator.java

@@ -35,6 +35,7 @@ import java.util.function.Predicate;
 import org.springframework.aot.generate.GeneratedMethods;
 import org.springframework.aot.hint.ExecutableMode;
 import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.aot.hint.TypeReference;
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.beans.PropertyValue;
@@ -128,6 +129,8 @@ class BeanDefinitionPropertiesCodeGenerator {
 
 	private void addInitDestroyMethods(Builder code, AbstractBeanDefinition beanDefinition,
 			@Nullable String[] methodNames, String format) {
+		// For Publisher-based destroy methods
+		this.hints.reflection().registerType(TypeReference.of("org.reactivestreams.Publisher"));
 		if (!ObjectUtils.isEmpty(methodNames)) {
 			Class<?> beanType = ClassUtils.getUserClass(beanDefinition.getResolvableType().toClass());
 			Arrays.stream(methodNames).forEach(methodName -> addInitDestroyHint(beanType, methodName));

spring-beans/src/test/java/org/springframework/beans/factory/aot/BeanDefinitionPropertiesCodeGeneratorTests.java

@@ -31,6 +31,7 @@ import javax.lang.model.element.Modifier;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
+import org.reactivestreams.Publisher;
 
 import org.springframework.aot.generate.GeneratedClass;
 import org.springframework.aot.hint.predicate.RuntimeHintsPredicates;
@@ -413,6 +414,7 @@ class BeanDefinitionPropertiesCodeGeneratorTests {
 		@Test
 		void noDestroyMethod() {
 			compile((beanDef, compiled) -> assertThat(beanDef.getDestroyMethodNames()).isNull());
+			assertReflectionOnPublisher();
 		}
 
 		@Test
@@ -420,6 +422,7 @@ class BeanDefinitionPropertiesCodeGeneratorTests {
 			beanDefinition.setDestroyMethodName("destroy");
 			compile((beanDef, compiled) -> assertThat(beanDef.getDestroyMethodNames()).containsExactly("destroy"));
 			assertHasMethodInvokeHints(InitDestroyBean.class, "destroy");
+			assertReflectionOnPublisher();
 		}
 
 		@Test
@@ -427,6 +430,7 @@ class BeanDefinitionPropertiesCodeGeneratorTests {
 			beanDefinition.setDestroyMethodName(privateDestroyMethod);
 			compile((beanDef, compiled) -> assertThat(beanDef.getDestroyMethodNames()).containsExactly(privateDestroyMethod));
 			assertHasMethodInvokeHints(InitDestroyBean.class, "privateDestroy");
+			assertReflectionOnPublisher();
 		}
 
 		@Test
@@ -434,6 +438,11 @@ class BeanDefinitionPropertiesCodeGeneratorTests {
 			beanDefinition.setDestroyMethodNames("destroy", privateDestroyMethod);
 			compile((beanDef, compiled) -> assertThat(beanDef.getDestroyMethodNames()).containsExactly("destroy", privateDestroyMethod));
 			assertHasMethodInvokeHints(InitDestroyBean.class, "destroy", "privateDestroy");
+			assertReflectionOnPublisher();
+		}
+
+		private void assertReflectionOnPublisher() {
+			assertThat(RuntimeHintsPredicates.reflection().onType(Publisher.class)).accepts(generationContext.getRuntimeHints());
 		}
 
 	}