Register test bean override infrastructure beans as singletons

Prior to this commit, AOT processing failed for tests that made use of
test bean override features, since the Set<OverrideMetadata>
constructor argument configured in the bean definition for the
BeanOverrideBeanFactoryPostProcessor could not be handled by our AOT
support.

To address that, this commit registers test bean override
infrastructure beans as singletons instead of via bean definitions with
the infrastructure role.

See spring-projectsgh-32933

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

@@ -17,13 +17,8 @@
 package org.springframework.test.context.bean.override;
 
 import java.util.Set;
-import java.util.function.Consumer;
 
-import org.springframework.beans.factory.config.BeanDefinition;
-import org.springframework.beans.factory.config.ConstructorArgumentValues;
-import org.springframework.beans.factory.config.RuntimeBeanReference;
-import org.springframework.beans.factory.support.BeanDefinitionRegistry;
-import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.test.context.ContextCustomizer;
 import org.springframework.test.context.MergedContextConfiguration;
@@ -57,43 +52,18 @@ class BeanOverrideContextCustomizer implements ContextCustomizer {
 
 	@Override
 	public void customizeContext(ConfigurableApplicationContext context, MergedContextConfiguration mergedConfig) {
-		if (!(context instanceof BeanDefinitionRegistry registry)) {
-			throw new IllegalStateException("Cannot process bean overrides with an ApplicationContext " +
-					"that doesn't implement BeanDefinitionRegistry: " + context.getClass());
-		}
-		registerInfrastructure(registry);
+		ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();
+		BeanOverrideRegistrar beanOverrideRegistrar = new BeanOverrideRegistrar();
+		beanOverrideRegistrar.setBeanFactory(beanFactory);
+		beanFactory.registerSingleton(REGISTRAR_BEAN_NAME, beanOverrideRegistrar);
+		beanFactory.registerSingleton(EARLY_INFRASTRUCTURE_BEAN_NAME, new WrapEarlyBeanPostProcessor(beanOverrideRegistrar));
+		beanFactory.registerSingleton(INFRASTRUCTURE_BEAN_NAME, new BeanOverrideBeanFactoryPostProcessor(this.metadata, beanOverrideRegistrar));
 	}
 
 	Set<OverrideMetadata> getMetadata() {
 		return this.metadata;
 	}
 
-	private void registerInfrastructure(BeanDefinitionRegistry registry) {
-		addInfrastructureBeanDefinition(registry, BeanOverrideRegistrar.class, REGISTRAR_BEAN_NAME,
-				constructorArgs -> {});
-
-		RuntimeBeanReference registrarReference = new RuntimeBeanReference(REGISTRAR_BEAN_NAME);
-		addInfrastructureBeanDefinition(registry, WrapEarlyBeanPostProcessor.class, EARLY_INFRASTRUCTURE_BEAN_NAME,
-				constructorArgs -> constructorArgs.addIndexedArgumentValue(0, registrarReference));
-		addInfrastructureBeanDefinition(registry, BeanOverrideBeanFactoryPostProcessor.class, INFRASTRUCTURE_BEAN_NAME,
-				constructorArgs -> {
-					constructorArgs.addIndexedArgumentValue(0, this.metadata);
-					constructorArgs.addIndexedArgumentValue(1, registrarReference);
-				});
-	}
-
-	private void addInfrastructureBeanDefinition(BeanDefinitionRegistry registry,
-			Class<?> clazz, String beanName, Consumer<ConstructorArgumentValues> constructorArgumentsConsumer) {
-
-		if (!registry.containsBeanDefinition(beanName)) {
-			RootBeanDefinition definition = new RootBeanDefinition(clazz);
-			definition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
-			ConstructorArgumentValues constructorArguments = definition.getConstructorArgumentValues();
-			constructorArgumentsConsumer.accept(constructorArguments);
-			registry.registerBeanDefinition(beanName, definition);
-		}
-	}
-
 	@Override
 	public boolean equals(Object other) {
 		if (other == this) {

spring-test/src/test/java/org/springframework/test/context/aot/AotIntegrationTests.java

@@ -145,7 +145,6 @@ void endToEndTestsForEntireSpringTestModule() {
 		runEndToEndTests(testClasses, false);
 	}
 
-	@Disabled("Comment out to run @TestBean integration tests in AOT mode")
 	@Test
 	void endToEndTestsForTestBeanOverrideTestClasses() {
 		List<Class<?>> testClasses = List.of(