Register runtime hints for OutputCapture

Closes gh-32870

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/system/OutputCapture.java

@@ -21,14 +21,19 @@ import java.io.OutputStream;
 import java.io.PrintStream;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Deque;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 
+import org.springframework.aot.hint.ExecutableMode;
+import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.aot.hint.TypeReference;
 import org.springframework.boot.ansi.AnsiOutput;
 import org.springframework.boot.ansi.AnsiOutput.Enabled;
+import org.springframework.test.context.aot.TestRuntimeHintsRegistrar;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
@@ -339,4 +344,15 @@ class OutputCapture implements CapturedOutput {
 
 	}
 
+	static class OutputCaptureRuntimeHints implements TestRuntimeHintsRegistrar {
+
+		@Override
+		public void registerHints(RuntimeHints runtimeHints, Class<?> testClass, ClassLoader classLoader) {
+			runtimeHints.reflection().registerType(TypeReference.of(OutputCapture.class),
+					(hint) -> hint.onReachableType(OutputCaptureExtension.class)
+							.withConstructor(Collections.emptyList(), ExecutableMode.INVOKE));
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-test/src/main/resources/META-INF/spring/aot.factories

@@ -0,0 +1,3 @@
+# Runtime hints for tests
+org.springframework.test.context.aot.TestRuntimeHintsRegistrar=\
+org.springframework.boot.test.system.OutputCapture.OutputCaptureRuntimeHints