Use isAssignableValue instead of isInstanceOf for argument resolution

Includes related nullability refinements.

Closes gh-28727

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

@@ -18,6 +18,7 @@ package org.springframework.beans.factory.aot;
 
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
 /**
  * Resolved arguments to be autowired.
@@ -38,11 +39,14 @@ public interface AutowiredArguments {
 	 * @param requiredType the required argument type
 	 * @return the argument
 	 */
-	@Nullable
 	@SuppressWarnings("unchecked")
+	@Nullable
 	default <T> T get(int index, Class<T> requiredType) {
-		Object value = get(index);
-		Assert.isInstanceOf(requiredType, value);
+		Object value = getObject(index);
+		if (!ClassUtils.isAssignableValue(requiredType, value)) {
+			throw new IllegalArgumentException("Argument type mismatch: expected '" +
+					ClassUtils.getQualifiedName(requiredType) + "' for value [" + value + "]");
+		}
 		return (T) value;
 	}
 
@@ -52,10 +56,10 @@ public interface AutowiredArguments {
 	 * @param index the argument index
 	 * @return the argument
 	 */
-	@Nullable
 	@SuppressWarnings("unchecked")
+	@Nullable
 	default <T> T get(int index) {
-		return (T) toArray()[index];
+		return (T) getObject(index);
 	}
 
 	/**
@@ -63,6 +67,7 @@ public interface AutowiredArguments {
 	 * @param index the argument index
 	 * @return the argument
 	 */
+	@Nullable
 	default Object getObject(int index) {
 		return toArray()[index];
 	}

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractAutowireCapableBeanFactory.java

@@ -1215,6 +1215,7 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 		return bw;
 	}
 
+	@Nullable
 	private Object obtainInstanceFromSupplier(Supplier<?> supplier, String beanName) {
 		String outerBean = this.currentlyCreatedBean.get();
 		this.currentlyCreatedBean.set(beanName);