Register runtime hints for BeanOverrideProcessors

This commit introduces a BeanOverrideReflectiveProcessor which
registers runtime hints for any BeanOverrideProcessor configured
via @⁠BeanOverride.

See gh-32933

spring-test/src/main/java/org/springframework/test/context/bean/override/BeanOverride.java

@@ -22,6 +22,8 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+import org.springframework.aot.hint.annotation.Reflective;
+
 /**
  * Mark a composed annotation as eligible for Bean Override processing.
  *
@@ -37,11 +39,13 @@ import java.lang.annotation.Target;
  * {@link org.springframework.test.context.bean.override.mockito.MockitoSpyBean @MockitoSpyBean}.
  *
  * @author Simon Baslé
+ * @author Sam Brannen
  * @since 6.2
  */
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.ANNOTATION_TYPE)
 @Documented
+@Reflective(BeanOverrideReflectiveProcessor.class)
 public @interface BeanOverride {
 
 	/**

spring-test/src/main/java/org/springframework/test/context/bean/override/BeanOverrideReflectiveProcessor.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2002-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.test.context.bean.override;
+
+import java.lang.reflect.AnnotatedElement;
+
+import org.springframework.aot.hint.ReflectionHints;
+import org.springframework.aot.hint.annotation.ReflectiveProcessor;
+import org.springframework.core.annotation.MergedAnnotation;
+import org.springframework.core.annotation.MergedAnnotations;
+
+import static org.springframework.aot.hint.MemberCategory.INVOKE_DECLARED_CONSTRUCTORS;
+
+/**
+ * {@link ReflectiveProcessor} that processes {@link BeanOverride @BeanOverride}
+ * annotations.
+ *
+ * @author Sam Brannen
+ * @since 6.2
+ */
+class BeanOverrideReflectiveProcessor implements ReflectiveProcessor {
+
+	@Override
+	public void registerReflectionHints(ReflectionHints hints, AnnotatedElement element) {
+		MergedAnnotations.from(element)
+				.get(BeanOverride.class)
+				.synthesize(MergedAnnotation::isPresent)
+				.map(BeanOverride::value)
+				.ifPresent(clazz -> hints.registerType(clazz, INVOKE_DECLARED_CONSTRUCTORS));
+	}
+
+}