Consistently set target type in generated code

Previously, a bean definition that is optimized AOT could have
different metadata based on whether its resolved type had a generic or
not. This is due to RootBeanDefinition taking either a Class or a
ResolvableType doing fundamentally different things. While the former
sets the bean class which is to little use with an instance supplier,
the latter specifies the target type of the bean.

This commit sets the target type of the bean, using the existing
setter methods that take either a class or a ResolvableType and set the
same attribute consistently.

Closes gh-30689

spring-beans/src/testFixtures/java/org/springframework/beans/testfixture/beans/factory/aot/TestHierarchy.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2002-2023 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.beans.testfixture.beans.factory.aot;
+
+/**
+ * A hierarchy where the exposed type of a bean is a partial signature.
+ *
+ * @author Stephane Nicoll
+ */
+public class TestHierarchy {
+
+	public interface One {
+	}
+
+	public interface Two {
+	}
+
+	public static class Implementation implements One, Two {
+	}
+
+	public static One oneBean() {
+		return new Implementation();
+	}
+
+}